Luminous Landscape Forum

Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: HSakols on February 12, 2018, 12:23:29 pm

Title: comparining micro four thirds to full frame
Post by: HSakols on February 12, 2018, 12:23:29 pm
Once again I haven't been super productive with my photography so instead of taking pictures, I'm over analyzing gear.  Last week I compared two images of the same subject taken with my Olympus EM5 and Nikon D800.  I was surprised to find out how subtle the differences are between the two files.  Yes, if I were making prints over 30 inches long, I'd get a real advantage of the full frame, but the difference in dynamic range is surprisingly small!  As someone who never prints over 20 inches long, I wonder if I 'm fooling myself with the full frame advantage.  However, I do see one advantage for me.  Controlling highlights and shadow details is much smoother using the full frame - I guess this is the dynamic range. 

Are any of you shooting full frame and not making huge prints.  Why do you stick with full frame?  It appears to me that for most images the difference is not enough to justify the added cost?
Title: Re: comparining micro four thirds to full frame
Post by: kers on February 12, 2018, 01:31:01 pm
because-
i just happen to do architectural and performance/cultural work so use 6400 asa as much as 64 asa.
The d850 is for me the camera that can do both really well, and the lenses are there to do everything i need/want.


Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on February 12, 2018, 01:39:56 pm
It appears to me that for most images the difference is not enough to justify the added cost?

See what happens with the FF noise advantage when matching DOF means pushing ISO:

(http://www.guillermoluijk.com/misc/mazinger.png)

Where are those FF super powers!?!

Regards


Enviado desde mi PRA-LX1 mediante Tapatalk

Title: Re: comparining micro four thirds to full frame
Post by: HSakols on February 12, 2018, 01:45:25 pm
Thanks for the examples!  I see the high ISO advantage, but being a landscape photographer, I rarely use more than my base ISO. 
Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on February 12, 2018, 01:48:52 pm
being a landscape photographer, I rarely use more than my base ISO.

And in case you do, you'll have less noise in the M4/3 because you'll need DOF, and that means losing 2 stops of light, as my example above shows.

Regards
Title: Re: comparining micro four thirds to full frame
Post by: armand on February 12, 2018, 02:11:10 pm
I've known the advantage of the smaller format when increased dof is needed but it's nice to have a picture associated with it. This brings good things for handheld shots in less than optimal light.

The problem is when you can afford to use the base ISO only (or close to it). For many shots it's good enough but occasionally you get one where the smaller sensor image begins to crumble much faster and you regret not having the larger camera.

For hiking the smaller sensor still usually win based on weight. It depends a lot on what lenses you bring with you too.
Title: Re: comparining micro four thirds to full frame
Post by: DP on February 12, 2018, 02:36:15 pm
See what happens with the FF noise advantage when matching DOF means pushing ISO:

(http://www.guillermoluijk.com/misc/mazinger.png)

Where are those FF super powers!?!

Regards


Enviado desde mi PRA-LX1 mediante Tapatalk

And why don't you use a FF sensor from EOS-1Ds (2002) to support your POV ?
Title: Re: comparining micro four thirds to full frame
Post by: DP on February 12, 2018, 02:46:23 pm
Are any of you shooting full frame and not making huge prints. 

I do not print, but I pixel peep ... and you do not need to stop down to have exactly the same DOF... you can simply use different focus distance, distance to subject and framing... and unlike Guillermo I do not consider deficient sensors to make a point - unless he wants to compare a pair of specific cameras (more over - you need to select optimal nominal ISOs on both cameras, not mechanically dial different iso to compensate for exposure changes - as it is not part of exposure) ...
Title: Re: comparining micro four thirds to full frame
Post by: Telecaster on February 12, 2018, 04:28:16 pm
I use the "full frame" cameras I own for the sake of specific lenses and for how the cameras themselves handle and operate. Lost interest in pixel-peeping format comparisons long ago. IMO pretty much everything on the market now delivers great real-world results provided you know how to use it. So do many cameras from the 2000s. What do you enjoy using? Go with that.

-Dave-
Title: Re: comparining micro four thirds to full frame
Post by: kers on February 12, 2018, 06:07:28 pm
And in case you do, you'll have less noise in the M4/3 because you'll need DOF, and that means losing 2 stops of light, as my example above shows.

Regards

Hai Guillermo, in your example i reckon the whole images on the FF is much larger than that of the 3/4 sensor- or am i mistaken?
The sense of more DOF is an illusion due to not enough resolution ... please correct me if you think i am wrong...
Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on February 12, 2018, 06:25:37 pm
Hai Guillermo, in your example i reckon the whole images on the FF is much larger than that of the 3/4 sensor- or am i mistaken?
The sense of more DOF is an illusion due to not enough resolution ... please correct me if you think i am wrong...
They were 24Mpx and 16Mpx from the A7 II and Olympus E-P5, using the same equivalent focal length (i.e. same framing), and the A7 slightly downsized to match the other picture. Aperture was then 2 stops closer in the FF to achieve the same DOF, and ISO pushed accordingly. Losing 2 stops of light puts the FF in a disadvantageous noise situation vs the M4/3 (or vs a crop of itself).

Regards
Title: Re: comparining micro four thirds to full frame
Post by: Two23 on February 12, 2018, 06:58:12 pm
Are any of you shooting full frame and not making huge prints.  Why do you stick with full frame?  It appears to me that for most images the difference is not enough to justify the added cost?

As a user of a Nikon D800E, yes, I think the "full frame" thing is about 75% hype (maybe more.)  When I'm on vacation or taking photos in a city (usually that's the same thing!) I mostly use a small Nikon D5300 with small lenses.  Or if in a very grungy dirty city (Chicago, San Francisco) I prefer to use a Nikon F3T or my Leica IIIc with b&w film!  So why keep the D800E?  Mostly for three reasons:  (1)  weddings.  I do like the bit of extended dynamic range in tricky light.  (2) portraits (and other paid work.)  I can make very big enlargements, for which I charge more.  (3)  tilt/shift lenses.  Not aware of any smaller cameras that can take wide angle versions of those, and my 24mm PC-E is my favorite lens of all!  What I would love is a small camera system, with Leica LTM sized lenses (or even Nikon AiS) that offers a couple of fully functioning tilt/shift lenses.  I can't live without them.  But yes, I think the "full frame" deal is way overhyped.


Kent in SD
Title: Re: comparining micro four thirds to full frame
Post by: BernardLanguillier on February 12, 2018, 09:02:19 pm
They were 24Mpx and 16Mpx from the A7 II and Olympus E-P5, using the same equivalent focal length (i.e. same framing), and the A7 slightly downsized to match the other picture. Aperture was then 2 stops closer in the FF to achieve the same DOF, and ISO pushed accordingly. Losing 2 stops of light puts the FF in a disadvantageous noise situation vs the M4/3 (or vs a crop of itself).

In reality there is often no issue at all to use a slower shutter speed when important DoF matters.

So the decision to use a constant shutter speed across formats is highly questionable in my view.

Cheers,
Bernard
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 12, 2018, 10:45:46 pm
As a user of a Nikon D800E, yes, I think the "full frame" thing is about 75% hype (maybe more.)  When I'm on vacation or taking photos in a city (usually that's the same thing!) I mostly use a small Nikon D5300 with small lenses.  Or if in a very grungy dirty city (Chicago, San Francisco) I prefer to use a Nikon F3T or my Leica IIIc with b&w film!  So why keep the D800E?  Mostly for three reasons:  (1)  weddings.  I do like the bit of extended dynamic range in tricky light.  (2) portraits (and other paid work.)  I can make very big enlargements, for which I charge more.  (3)  tilt/shift lenses.  Not aware of any smaller cameras that can take wide angle versions of those, and my 24mm PC-E is my favorite lens of all!  What I would love is a small camera system, with Leica LTM sized lenses (or even Nikon AiS) that offers a couple of fully functioning tilt/shift lenses.  I can't live without them.  But yes, I think the "full frame" deal is way overhyped.


All these points are very relevant, but any comparison between the qualities of a cropped format and a full-frame format should exclude all features which are not directly related to the differences in format size.

Comparing different brands of cameras introduces a whole range of different features which are not related to format size. The only sensible comparison is between two different formats that have the same size and quality of pixels and which can use the same lenses.

The closest example I'm aware of is the 16mp Nikon D7000 cropped-format compared with the 36mp full-frame Nikon D800. The pixel quality and pixel size is almost exactly the same for both cameras.

So let's consider the advantages of the D800 in such a comparison.
Let's compare how the two cameras perform with a single prime lens such as a 50mm F1.4.

(1) The lens on the D7000 is effectively a 75mm prime. However, in relation to the general quality of the image that can be produced by the D7000, the D800 provides an exceptionally high quality 50-75mm F1.4 zoom.
How much would such a zoom lens cost, if it were available, and how much would it weigh?
If such a lens were available for the D7000 it would be a 33-50mm F1.4 zoom.

(2) A similar situation applies to all full-frame lenses that fit the two cameras. Let's say your favourite lens is a 400mm F2.8 prime for bird shots. On the D7000 it becomes an impressive 600mm lens. However, on the D800 it becomes an even more impressive 400-600mm/F2.8 zoom, in relation to the maximum image quality of the D7000.

To get an equivalent range of focal lengths on the D7000, you would need a 266-400mm/F2.8 zoom. I suspect that the weight of such a zoom plus the D7000 body would exceed the weight of the D800 plus 400/F2.8 prime. Not only that, the quality of a zoom lens at every focal length rarely matches the quality of a good prime lens at the same focal length.

Also, when downsizing the D800 image at 400mm to match the size of the D7000 image at 266mm focal length, both the noise and sharpness of the D800 image will be better. If one considers such an improvement insignificant, then that's fine, but that's just a bonus in addition to the free conversion of all one's prime lenses to short-range zoom lenses, and the conversion of all one's zoom lenses to extended-range zooms at the wide end.

However, if one is comparing a cropped format which has smaller pixels, but of approximately equal quality to the larger pixels of the full-frame format, such as the D7200 compared with the D800, then the cropped format will have a resolution advantage with the same lens, but I doubt such a resolution advantage would be significant comparing the D7200 with the new D850.
Title: Re: comparining micro four thirds to full frame
Post by: Two23 on February 12, 2018, 11:49:22 pm
All these points are very relevant, but any comparison between the qualities of a cropped format and a full-frame format should exclude all features which are not directly related to the differences in format size.

Comparing different brands of cameras introduces a whole range of different features which are not related to format size. The only sensible comparison is between two different formats that have the same size and quality of pixels and which can use the same lenses.



I understand your point; you seem to be taking a more specific "apples to apples" approach.  I take a different approach in that I don't look at camera gear as individual pieces, but rather as a complete system.  Thus, a camera system that doesn't have tilt/shift lenses (or good off-camera flash capability) would rule out my using it as my "main" system right there.


Kent in SD
Title: Re: comparining micro four thirds to full frame
Post by: BernardLanguillier on February 12, 2018, 11:56:40 pm
I understand your point; you seem to be taking a more specific "apples to apples" approach.  I take a different approach in that I don't look at camera gear as individual pieces, but rather as a complete system.  Thus, a camera system that doesn't have tilt/shift lenses (or good off-camera flash capability) would rule out my using it as my "main" system right there.

Along the same lines:
- you cannot get a micro 3/4 camera with an optical viewfinder
- you cannot get a micro 3/4 camera with a profoto air remote
- you cannot get a micro 3/4 camera with the equivalent of a 200mm f2.0 or 105 f1.4 in terms of subject isolation (more DoF isn't always the prefered rendering)

Cheers,
Bernard
Title: Re: comparining micro four thirds to full frame
Post by: langier on February 13, 2018, 01:47:19 am
I have both a pair of D800 and Oly 5DII bodies.

Before the 5DII, shooting a pair of Panasonic GX-7 bodies, there was no comparison: The D800 too the prize in IQ, noise, DR, overall files and in large prints. I traveled with both and when IQ was needed for my work, the D800 was the go-to.

Then I got a Oly 5DII. For some of my specialty work (circular fisheye), it got me close enough with with high-res mode that for a lot of my work, the Nikon stays home now. For a lot of my work, smaller 16MB captures are fine. Best of all, is the size, weight and silence of the M43 that I'm fairly happy with the results.

When I travel, the M43 system is 2/3rds the size and weight and that includes a few extra parts I use for video that I didn't have the room to carry with the D800. The bulk is much less, too, and I can carry an even wider range of lenses.

In the past few months, I've needed to push the ISO to nose-bleed speeds with the Oly, 3200-12800. Though the 12800 is noisy, the images for a lot of what I need is fine. Where the Oly really rises to the top is using the High-res mode on a tripod. The Oly 12-40 and the Panasonic 35-100 hold their own against the equivalent FX Nikkor lenses. Other than a little purple flare with the Vario 7-14, it's as good as my 14-24 but a stop slower and less ghosting. The Oly and 7-14 is smaller and lighter than that lens alone.

With good craft, lower ISO and the high-res mode, the files are close to the D800 and when it comes to large prints, it's hard to tell which of the two cameras was used.

I've now shot M43 for about 5 years and the Oly 5II for a couple, Nikons for decades and Nikon D for more than 15. At this time in my life, I could probably simply shoot just the Oly and be happy just because it's so small, light and quite and totally adequate image quality for I'd say up to 16x20 and beyond, especially with good craft.
Title: Re: comparining micro four thirds to full frame
Post by: hogloff on February 13, 2018, 01:54:08 am
In reality there is often no issue at all to use a slower shutter speed when important DoF matters.

So the decision to use a constant shutter speed across formats is highly questionable in my view.

Cheers,
Bernard

Exactly. Many of my landscape images are shot at base iso with the aperture I need to get the DOF I want...and then let the shutter be whatever it needs to be to make the image.
Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on February 13, 2018, 02:15:28 am
In reality there is often no issue at all to use a slower shutter speed when important DoF matters.

So the decision to use a constant shutter speed across formats is highly questionable in my view.

You are probably thinking of tripod applications Bernard, and I agree. But I meant the case when high ISO is needed to have all in focus, e.g. hanheld, because this sets a mininum shutter speed requirement.

Surprisingly (or not so much if one understands the physics and statistiscs) a mobile phone can be more capable of producing clean high DOF hanheld images in low light conditions than a FF camera. For instance night or poorly lit indoor scenes.

Normally photographers sacrifice DOF for SNR in these situations and shoot wider open, but if large DOF is an inescapable must the larger formats are beaten by the tinier ones.

(http://www.guillermoluijk.com/misc/s7vsa7.png)

Ignore the different sizes, since different equivalent focal lenghts were used. But the images were resized to the same resolution to make a fair noise comparison. Both images were developed with the same neutral parameters (DCRAW), no noise reduction. FF wins at sharpness (I wouldn't expect less from a 2000EUR lens), but the S7 is less noisy.

Regards
Title: Re: comparining micro four thirds to full frame
Post by: BernardLanguillier on February 13, 2018, 03:27:29 am
You are probably thinking of tripod applications Bernard, and I agree. But I meant the case when high ISO is needed to have all in focus, e.g. hanheld, because this sets a mininum shutter speed requirement.

Surprisingly (or not so much if one understands the physics and statistiscs) a mobile phone can be more capable of producing clean high DOF hanheld images in low light conditions than a FF camera. For instance night or poorly lit indoor scenes.

Normally photographers sacrifice DOF for SNR in these situations and shoot wider open, but if large DOF is an inescapable must the larger formats are beaten by the tinier ones.

Agreed.

Others may differ, but for my - pretty diverse - applications, it is very rare for me to need a lot of DoF and not to be able to use a tripod.

But I agree it can happen and smaller sensors do have an advantage then.

Cheers,
Bernard
Title: Re: comparining micro four thirds to full frame
Post by: 32BT on February 13, 2018, 03:48:58 am
Surprisingly (or not so much if one understands the physics and statistiscs) a mobile phone can be more capable of producing clean high DOF hanheld images in low light conditions than a FF camera. For instance night or poorly lit indoor scenes.

But your comparison seems to suggest that f/1.7 on the Samsung is comparable to f/14 on FF. That seems a bit stark for the purposes mentioned, no? It is not surprising at all that certain high iso on any larger format leads to more noise than a phone at base iso. But for more-or-less equivalent DoF, especially considering the theoretical example, the lowest possible f number should be chosen instead. The lowest equivalent on FF would be something like 5.6, wouldn't it?
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 13, 2018, 08:30:48 am
Smaller sensors do not have an advantage unless the quality of the pixels, in relation to their size, is better than the larger pixels.

In other words, if the pixel is half the size and half the quality, there is no advantage. If the pixel is half the size but 2/3rds of the quality of the pixel which is double the size, then one can expect an improvement.

In Guillermo's example of the Samsung S7 versus the Sony A7 II, the Sony image looks far better to me.
Title: Re: comparining micro four thirds to full frame
Post by: PeterAit on February 13, 2018, 09:20:47 am
Another consideration is that the camera you have with you is always better than the camera you left home because it's too bulky and heavy. With my E-M1 and two zoom lenses I have a 24-600mm equiv range in a compact, lightweight kit. Can you imagine trying to get the same capabilities with FF gear?

Also worthy of thought are the newer "bridge" cameras with a 1" sensor, specifically the Sony RX10. There have been enormous strides in lens and sensor design and I am amazed at the image quality.
Title: Re: comparining micro four thirds to full frame
Post by: DP on February 13, 2018, 09:28:30 am
Another consideration is that the camera you have with you is always better than the camera you left home because it's too bulky and heavy. With my E-M1 and two zoom lenses I have a 24-600mm equiv range in a compact, lightweight kit. Can you imagine trying to get the same capabilities with FF gear?

why somebody must imagine capabilities that you are looking for ? I always use one dSLM camera and one prime (in 35mm ... 85mm range) - so "FF" size is not an issue... now having said that E-M1 line has a very good body, I have nothing against having Sony FF sensor in Olympus E-M1 style body ...

Title: Re: comparining micro four thirds to full frame
Post by: Kirk_C on February 13, 2018, 01:03:03 pm
This discussion brings an older Zack Arias rant (https://youtu.be/PHYidejT3KY) to mind.
Title: Re: comparining micro four thirds to full frame
Post by: kers on February 14, 2018, 10:36:57 am
Another consideration is that the camera you have with you is always better than the camera you left home because it's too bulky and heavy. With my E-M1 and two zoom lenses I have a 24-600mm equiv range in a compact, lightweight kit. Can you imagine trying to get the same capabilities with FF gear?

Also worthy of thought are the newer "bridge" cameras with a 1" sensor, specifically the Sony RX10. There have been enormous strides in lens and sensor design and I am amazed at the image quality.
yes there are a lot of good reasons to pick a camera that have nothing to do with choosing a sensor size.
FF has grown onto me and serves me well for what i do.
And FF includes all smaller sizes sensors...

Title: Re: comparing micro four thirds to full frame
Post by: BJL on February 15, 2018, 11:47:08 am
We seem to be getting evidence and arguments for the idea that larger format cameras have their clearest advantage when used on a tripod at low exposure index (so-called "ISO") and longer exposure times than would be used with a smaller format. This might be surprising given all the digital-era emphasis on the better high-speed capabilities of larger formats, but is totally in accord with the pattern of use cases for larger film formats.

Of course, there is another advantage of a larger format: when very shallow DOF the bigger, heavier lenses are either tolerable for the sake of handling low-light and moving subjects, or when low DOF is desired for things like the artistic effect of strong background blurring. But this seems a bit less important to the main interests of the Luminous Landscape audience.

P. S. Ray, as discussed many times over the years here at LuLa, there are inherent technical reasons backed by experimental data as to why one is likely to get likely to get less noise in a smaller format at a given EI (e.g ISO 200 in 4/3" format) than with a larger sensor at the higher EI used to get equal DOF and exposure time in a larger format (e.g. ISO 800 in 35mm format).  In a nutshell: because in this particular scenario, there will be about the same photon count and amount of photon shot noise, but the larger sensor (and longer, wider signal paths and larger components in the analog signal processing path) will generate more electrical noise.
Title: Re: comparing micro four thirds to full frame
Post by: Ray on February 15, 2018, 08:19:56 pm

P. S. Ray, as discussed many times over the years here at LuLa, there are inherent technical reasons backed by experimental data as to why one is likely to get likely to get less noise in a smaller format at a given EI (e.g ISO 200 in 4/3" format) than with a larger sensor at the higher EI used to get equal DOF and exposure time in a larger format (e.g. ISO 800 in 35mm format).  In a nutshell: because in this particular scenario, there will be about the same photon count and amount of photon shot noise, but the larger sensor (and longer, wider signal paths and larger components in the analog signal processing path) will generate more electrical noise.

BJL,
Of course, there are usually many technical differences between all brands and sizes of cameras. Nobody buys a camera based on the consideration of just one factor, such as format size. (At least, I don't).
There is usually a huge range of technical and cost advantages, and disadvantages to consider, in relation to one's purpose, and usual photographic method and style.

For some folks, weight is a major consideration, and most people would be willing to sacrifice to some degree the potential quality and resolution of an image for the sake of the convenience of low weight. The question then becomes a matter of degree. 'How much is the weight saving, and how much is the image-quality loss?' A significant weight-saving with the consequences of an insignificant or less significant loss of image quality, would probably appeal to most people, provided there was no major increase in price.

However, as you know, I'm a great fan of the scientific method. When considering the effects of just one factor, such as format size, one needs to keep all other factors the same, if possible, otherwise the effects of that one factor become confused with the other factors.

So, to get back to my main point, if the pixel size and quality is the same for both formats, after all the in-camera processing of the signal is complete, as it is comparing the Nikon D7000 with the Nikon D800, (according to DXOMark) then the larger format has all the advantages and no disadvantages.

The larger format then becomes 'effectively' cheaper, lighter, and, over all, produces better image quality (and no less than equal image quality, at a minimum, in certain circumstances when the larger format is cropped to the same size as the smaller format).

Now, if you escape from the scientific method, and include all sorts of other factors not directly related to format size, and exclude certain disadvantages of the smaller format in terms of the general lack of flexibility of the focal lengths of whatever lenses are used, then you might as well stick with your iPhone camera.  ;)

To repeat, a D7000 with 50mm/F1.4 prime, might be lighter and cheaper than a D800 with the same 50mm prime but is not capable of capturing the same subject matter from the same position. If you don't have the time to move further back, or as is often the case, don't have the physical possibility of moving back, then you've lost the shot.

To give the smaller format that capability, you'd need a very high quality, and very expensive 33-50mm/F1.4 zoom. At 50mm, the quality of the images from both cameras would be the same (provided the zoom lens was of equal quality to the 50mm prime). However, at 33 mm on the D7000 the image quality would be worse (in terms of resolution and noise), although the angle of view would be the same as that from the 50mm prime on the D800. But at least you would not have missed the shot.

The extra weight and cost of a 33-50mm/F1.4 zoom lens would make the D7000 at least as expensive and at least as heavy as the D800 with 50mm prime. Okay?
Title: Re: comparining micro four thirds to full frame
Post by: HSakols on February 16, 2018, 11:51:18 am
Ray,
 
I know I'm beating a dead horse and I see what you're saying but...  Take an Olympus 25 1.2 lens and compare it to your Nikon 50 1.4.  You won't see any difference other than probably a sharper image with the Olympus.  Print these two below 16x20 and there is no difference other than weight. 

I will say that I do prefer the Nikon for silky smooth control and I like a large view finder. For people like myself it is probably best to have both.
Title: Re: comparining micro four thirds to full frame
Post by: GuyPhoto on February 16, 2018, 12:36:15 pm
Along the same lines:
- you cannot get a micro 3/4 camera with an optical viewfinder
- you cannot get a micro 3/4 camera with a profoto air remote
- you cannot get a micro 3/4 camera with the equivalent of a 200mm f2.0 or 105 f1.4 in terms of subject isolation (more DoF isn't always the prefered rendering)


True, you cannot get a micro 4/3 camera with an optical viewfinder, but you are wrong on the Profoto Air Remote (one has been available for some time).

As far as subject isolation, the lens and sensor are not the only variables. By moving closer to the subject and thereby compressing DOF and altering the ratio between subject and background, I can get reasonable isolation with my M4/3 lens set, even razor thin. A few minutes with a DOF calculator and years in the studio taught me that. Someone did a wonderful blog piece illustrating that with various camera systems, and I am always annoyed I lost the link.  Of course, sometimes it is not feasible or comfortable to get close, but every lens and camera combo limits your positioning to some degree. Those $2K -$6K lenses you cite DO make the isolation easier, but at a cost, which in some circumstances can be justified. Photography comes down to problem solving, and there are many ways to solve a problem depending on your budget and how much gear you want to carry.
Title: Re: comparining micro four thirds to full frame
Post by: petermfiore on February 16, 2018, 02:46:56 pm

Photography comes down to problem solving, and there are many ways to solve a problem depending on your budget and how much gear you want to carry.

Absolutely...!00%

Peter
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 16, 2018, 06:48:19 pm
Ray,
 
I know I'm beating a dead horse and I see what you're saying but...  Take an Olympus 25 1.2 lens and compare it to your Nikon 50 1.4.  You won't see any difference other than probably a sharper image with the Olympus.  Print these two below 16x20 and there is no difference other than weight. 

I will say that I do prefer the Nikon for silky smooth control and I like a large view finder. For people like myself it is probably best to have both.

Your above statement is very confusing, Hugh. Are you talking about the 16mp Olympus E-M5 with 25mm lens, compared with the 36mp Nikon D800 with 50mm lens?

The following DXOMark link shows there would be a huge, or at least a significant difference in all the metrics they address, such as SNR, DR, Tonal Range and Color Sensitivity.

At base ISO, the D800 shot would have around 5.7db better SNR (3dB is in the noticeable range). DR is almost 2 stops better, at its lower base ISO, or at least 1.5 stops better at the same actual ISO sensitivity.

Comparing the quality of the individual pixels, the Nikon D800 pixel still has around around 1.3 stops better DR at low ISO's, but approximately the same DR at very high ISO's. The SNR of the Nikon pixel is around 2dB better across the entire ISO range. There is no measurement on the DXO graphs which shows the EM5 pixel is better in any way at any ISO.

So what's the comparison if you crop the images from both cameras to get an effective 100 mm lens from the attached 50 mm lens on the Nikon and the 25mm lens on the Olympus?

Wouldn't you be comparing something like 4mp from the Olympus with 9mp from the Nikon? Are you claiming there would be no significant difference in image quality on, say, an A2 or A3 print?

https://www.dxomark.com/Cameras/Compare/Side-by-side/Olympus-OM-D-E-M5-Mark-II-versus-Nikon-D800___1006_792


Title: Re: comparining micro four thirds to full frame
Post by: HSakols on February 16, 2018, 08:03:01 pm
Quote
Wouldn't you be comparing something like 4mp from the Olympus with 9mp from the Nikon? Are you claiming there would be no significant difference in image quality on, say, an A2 or A3 print?

Exactly
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 16, 2018, 09:08:30 pm
Exactly

You specialize in fuzzy abstracts, do you?  ;D
Title: Re: comparining micro four thirds to full frame
Post by: hogloff on February 17, 2018, 11:31:14 am
Ray,
 
I know I'm beating a dead horse and I see what you're saying but...  Take an Olympus 25 1.2 lens and compare it to your Nikon 50 1.4.  You won't see any difference other than probably a sharper image with the Olympus.  Print these two below 16x20 and there is no difference other than weight. 

I will say that I do prefer the Nikon for silky smooth control and I like a large view finder. For people like myself it is probably best to have both.

You are only looking at resolutions here. What about dynamic range which is hugely important in many landscape images. What about tonal gradation which is very important in many landscapes. You need to take the full package into account and I'm sorry, but I just do not agree with your view.
Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on February 17, 2018, 12:11:33 pm
What about tonal gradation which is very important in many landscapes.

Tonal gradation is a myth. A mobile phone can provide the same quality regarding tonal gradation as a MF sensor because no matter the sensor size, there are many more tone levels in any RAW file than our eyes can catch. In addition to that, noise dithers it all, just look at the histogram of this noisy gradation:

(http://www.guillermoluijk.com/misc/degradado_oscuro_5bits.png)

Another story is colour accuracy and colour gamut, but that is not gradation. BTW the 'Tonal range' measurement in DxOMark is just another benchmark based on noise, so good tonal range in DxOMark is just 'low noise' sensor.

I have been looking for a tonal gradation comparison between cameras for years. It simply doesn't exist, just users talking about 'tonal gradation'.

Regards
Title: Re: comparining micro four thirds to full frame
Post by: hogloff on February 17, 2018, 02:37:56 pm
Tonal gradation is a myth. A mobile phone can provide the same quality regarding tonal gradation as a MF sensor because no matter the sensor size, there are many more tone levels in any RAW file than our eyes can catch. In addition to that, noise dithers it all, just look at the histogram of this noisy gradation:

(http://www.guillermoluijk.com/misc/degradado_oscuro_5bits.png)

Another story is colour accuracy and colour gamut, but that is not gradation. BTW the 'Tonal range' measurement in DxOMark is just another benchmark based on noise, so good tonal range in DxOMark is just 'low noise' sensor.

I have been looking for a tonal gradation comparison between cameras for years. It simply doesn't exist, just users talking about 'tonal gradation'.

Regards

Well it really doesn’t matter what causes the tonal gradition differences, but I see much smoother tonal variations with my A7R images than my 7d images. Really don’t care if it’s caused by a difference in noise, the end result is what counts and I do get better tonal ranges with the A7R images.
Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on February 17, 2018, 03:31:16 pm
I see much smoother tonal variations with my A7R images than my 7d images.

I would love to see those smoother tonal variations A7R vs 7D. Just an example will suffice. I assume you shot the same scenes with both cameras and developed the RAW files in an indentical way.

Regards
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 17, 2018, 08:11:56 pm
Quote
Quote from: HSakols on February 16, 2018, 11:51:18 AM
Ray,

I know I'm beating a dead horse and I see what you're saying but... Take an Olympus 25 1.2 lens and compare it to your Nikon 50 1.4. You won't see any difference other than probably a sharper image with the Olympus. Print these two below 16x20 and there is no difference other than weight.

I will say that I do prefer the Nikon for silky smooth control and I like a large view finder. For people like myself it is probably best to have both.


You are only looking at resolutions here. What about dynamic range which is hugely important in many landscape images. What about tonal gradation which is very important in many landscapes. You need to take the full package into account and I'm sorry, but I just do not agree with your view.

I don't think Hugh is specifically addressing resolution, but is addressing the other factors that obscure the perception of resolution, such as print size, viewing distance, and lens quality.

The Nikon D800 pixel is approximately the same size as the Olympus EM5 pixel, but is slightly better quality over all, and noticeably better quality with regard to DR at base ISO.

There's no way a 16mp Olympus 4/3rds format will match the resolution of a 36mp Nikon D800, even if the Olympus 25mm/F1.2 is a better lens than the standard Nikkor 50mm, which it might be when heavily cropping the Nikon image.

Nevertheless, at a 100mm focal length equivalent for both cameras, we are comparing Olympus 4mp with Nikon 9mp. Assuming the scene being photographed contains fine detail and a wide brightness range, one would expect the 9mp Nikon image to show more detail and better DR on an A2 size print, when viewed close up.
Title: Re: comparining micro four thirds to full frame
Post by: scooby70 on February 18, 2018, 05:14:31 am
Once again I haven't been super productive with my photography so instead of taking pictures, I'm over analyzing gear.  Last week I compared two images of the same subject taken with my Olympus EM5 and Nikon D800.  I was surprised to find out how subtle the differences are between the two files.  Yes, if I were making prints over 30 inches long, I'd get a real advantage of the full frame, but the difference in dynamic range is surprisingly small!  As someone who never prints over 20 inches long, I wonder if I 'm fooling myself with the full frame advantage.  However, I do see one advantage for me.  Controlling highlights and shadow details is much smoother using the full frame - I guess this is the dynamic range. 

Are any of you shooting full frame and not making huge prints.  Why do you stick with full frame?  It appears to me that for most images the difference is not enough to justify the added cost?

I have a Sony A7 and a couple of Panasonic MFT cameras. I still print sometimes and maybe average a print a week but not often large now.

Years ago when I first bought into MFT with a Panasonic GF1 and then a G1 I did a lot of comparisons with my Canon 5D and 20D and concluded that if I didn't pixel peep or take a magnifying glass to what was already a good sized print there wasn't a lot in it between any of them and other people I roped in didn't seem to know what I was looking for. The 5D had a bit more DR I suppose but surprisingly I could boost the MFT files quite a lot without them felling apart whereas when I boosted the Canon files they showed noise in the shadows pretty quickly so things tended to even out a bit.

These days with my Sony A7 and Panasonic GX7 and GX80 the situation is pretty similar but maybe the A7 opens up a little more of a gap than the 5D did. The A7 has more DR and gives a sharper result and overall better image quality and the files can be processed a lot without falling apart but having said all that mostly no one will notice any shortcomings in the MFT pictures and my MFT pictures are easily better than anything I got from 35mm film. YMMV.

I tend to use the A7 when I want the best quality I can get and when I want to be able to use lovely old manual lenses at their original field of view. I tend to use MFT when I want to be more discrete as I think sometimes even a small Sony A7 can be too attention grabbing. My MFT cameras are also much faster so I use them when I want to be discrete or fast or both.
Title: Re: comparining micro four thirds to full frame
Post by: Emmett on February 18, 2018, 12:37:36 pm
I have recently uploaded an analytical work on M4/3 and I thought it might be interesting for some readers here:

https://multianalytics.blog/2018/02/18/a-brief-m4-3-statistical-sensor-classification-between-panasonic-and-olympus-in-combination-with-cropped-f-and-full-f-has-m4-3-reached-its-limits/
Title: Re: comparing micro four thirds to full frame
Post by: BJL on February 18, 2018, 05:18:54 pm
...  a D800 with the same 50mm prime but is not capable of capturing the same subject matter from the same position. If you don't have the time to move further back, or as is often the case, don't have the physical possibility of moving back, then you've lost the shot.

To give the smaller format that capability, you'd need a very high quality, and very expensive 33-50mm/F1.4 zoom.
Ray, you have in a rather quirky way illustrated my second point, on which we all seem to agree: if and when the best results in the larger format involve using a sufficiently low aperture ratio, then it is harder or impossible to get those results in a smaller format. That is, whenever you choose to be at or near the low DOF limit of the larger format.

Given the extra cost and weight involved in using a larger format, especially when equipped with the lenses that offer those large apertures and related advantages in low light/high shutter speed situations, some questions to ask are:
Would some of the images from one's current format, when displayed and viewed as one wishes, benefit from
- larger apertures than the current format allows? (For more OOF blurring, less noise at high enough shutter speeds, etc.)
- less visible shadow noise and finer tonal gradations in the deep shadows? (I agree mostly with Guillermo Luijk that a larger sensor does not give finer tonal gradations other than in the deep shadows, because elsewhere, the gradations and local SNR ratio in the smaller ILC formats are already far finer than the eye can distinguish.)
- more visible fine detail, in the sense of more "lines per picture height" of resolution? (Achieved if the sensor and the lens and aperture choice combine provide that — not true when the current format is already constrained by DOF and diffraction trade-offs.)


Of course, if the answer for the user of 4/3" format [22mm diagonal] is "yes, often enough", the next question is whether the step to a good 24x16mm [28mm diagonal] format system is enough to scratch those itches, or if instead the jump to 36x24mm [42mm diagonal] or 44x33mm [55mm diagonal] or even beyond is worthwhile.
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 18, 2018, 05:32:53 pm
The Nikon D800 pixel is approximately the same size as the Olympus EM5 pixel, but is slightly better quality over all, and noticeably better quality with regard to DR at base ISO.
The D800 pixels are of just under twice the area, and so about 1.4x greater linear size compared to EM5 pixels. The same is roughly true with the newer 45MP D850 and 20MP MFT sensors. In fact, this pattern has been surprising steady, with 36x24mm format having about twice the pixel count, twice the pixel area and so a 1.4x higher image resolution ("lines per picture height") and 1.4x lower sensor resolution ("lines per mm") — even since it was 5MP in 4/3", 11 to 14MP in 36x24mm.
Title: Re: comparing micro four thirds to full frame
Post by: Ray on February 18, 2018, 09:18:20 pm
Ray, you have in a rather quirky way illustrated my second point, on which we all seem to agree: if and when the best results in the larger format involve using a sufficiently low aperture ratio, then it is harder or impossible to get those results in a smaller format. That is, whenever you choose to be at or near the low DOF limit of the larger format.

Given the extra cost and weight involved in using a larger format, especially when equipped with the lenses that offer those large apertures and related advantages in low light/high shutter speed situations, some questions to ask are:
Would some of the images from one's current format, when displayed and viewed as one wishes, benefit from
- larger apertures than the current format allows? (For more OOF blurring, less noise at high enough shutter speeds, etc.)
- less visible shadow noise and finer tonal gradations in the deep shadows? (I agree mostly with Guillermo Luijk that a larger sensor does not give finer tonal gradations other than in the deep shadows, because elsewhere, the gradations and local SNR ratio in the smaller ILC formats are already far finer than the eye can distinguish.)
- more visible fine detail, in the sense of more "lines per picture height" of resolution? (Achieved if the sensor and the lens and aperture choice combine provide that — not true when the current format is already constrained by DOF and diffraction trade-offs.)


Of course, if the answer for the user of 4/3" format [22mm diagonal] is "yes, often enough", the next question is whether the step to a good 24x16mm [28mm diagonal] format system is enough to scratch those itches, or if instead the jump to 36x24mm [42mm diagonal] or 44x33mm [55mm diagonal] or even beyond is worthwhile.

Hi BJL,
It's important to know what the differences actually are, and be aware of the visible significance of the differences in specific situations that are relevant to the nature of your photographic activities. That's why I find DXOmark a very useful site.

For me, the issues of price, weight and general flexibility of the system are very relevant. I'm always prepared to sacrifice a certain degree of technical image quality for the sake of a lighter, less expensive and more flexible system. That's why I've never been able to justify the purchase of those ridiculously expensive and heavy MF digital cameras and lenses.

However, the extra weight of a D800 body, compared with a D7000 body which has pixels of equal quality and size, is a mere 240 gms, which is also the same weight difference between the new D850 and the D7200. When I consider the 'effective' extended range of all lenses attached to the full frame body (compared with the same lens on the cropped-format body), then the slight extra weight of the full-frame body, plus the modest increase in the initial purchase price of the full-frame body, seem well-justified to me.

However, I realize that this situation of being able to use the same lenses on the two different formats does not apply to the Olympus 4/3rds system. A lens which is specifically designed for the smaller format can be lighter, so there can be a combined weight-saving of both lens and body, except when one chooses a lens which can mimic the effective focal length range, and wide-aperture DoF effects, of the equivalent lens on a full-frame.

For example, if you consider that 16mp is your minimum standard for all your purposes of future printing, cropping and display, then to get the same flexibility on an Olympus E-M5 as you could get on a Nikon D800, in relation to that required minimum pixel count of 16mp, the lens on the Olympus 4/3rds that would be fully equivalent to a standard 50mm/F2.8 lens on the D800, would need to be a 25-50mm/F1.4 zoom.

I wonder what the weight of a 25-50/F1.4 zoom designed for the 4/3rds format would be?  ;)

However, I agree we haven't really got full equivalence in this comparison because there are other advantages to a wider aperture, apart from a shallower DoF. One can use a faster shutter speed to freeze movement, and/or use a lower ISO setting in poor light, which can improve image quality.

On the other hand, the full D800 image, when downsized to the 16mp of the E-M5, will tend to have improved noise and resolution which will at least partially offset the lower noise of the Olympus shot at 25mm/F1.4, as opposed to 50mm/F2.8 on the D800. Agreed?

Also, if this is an issue, then using a Nikkor 50/F1.4 instead of 50/F2.8 removes that advantage of a 25-50mm/F1.4 zoom on the 4/3rds format. I don't think it would be realistic to expect anyone to manufacture a 20-50mm/F0.7 zoom.  :D
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 18, 2018, 09:22:57 pm
The D800 pixels are of just under twice the area, and so about 1.4x greater linear size compared to EM5 pixels. The same is roughly true with the newer 45MP D850 and 20MP MFT sensors. In fact, this pattern has been surprising steady, with 36x24mm format having about twice the pixel count, twice the pixel area and so a 1.4x higher image resolution ("lines per picture height") and 1.4x lower sensor resolution ("lines per mm") — even since it was 5MP in 4/3", 11 to 14MP in 36x24mm.

Yes. I was confusing the comparison between the D7000 and the D800. The 4/3rds sensor is smaller than the DX D7000 sensor, yet they both have the same number of pixels, so the MFT pixels must be smaller. The full frame Nikon FX cameras have 2.25x the area of the cropped format DX, so the 36mp of the D800 sensor divided by 2.25 = 16, the pixel count of the D7000.

Thanks for pointing that out, because there are other ramifications which I've got wrong. 50mm on the E-M5 produces an effective FF focal length of 100mm, with the full 16mp. However, 50mm on the D800, cropped to the same angle of view, results in a 9mp image, so the image from the E-M5 in these circumstances should be at least slightly better, at least in the centre of the image.

In the corners and edges, the heavily cropped D800 image might be better.

However, this discrepancy of pixel count works both ways. If one has a 25mm prime on the E-M5, and one want's the equivalent angle of view of a 100mm lens, full frame, then one has to crop the 16mp E-M5 image to just 4mp.

On the D800, to get an equivalent 100mm angle of view with a 50mm lens, one needs to crop to 9mp.
If Hugh thinks there is no quality difference between cropped 4mp and cropped 9mp images on an A2 size print, then there's even more reason to think there would be no difference between a cropped 9mp image and the full E-M5 16mp image. Agreed?




Title: Re: comparing micro four thirds to full frame
Post by: BJL on February 18, 2018, 10:29:01 pm
Ray,

However, the extra weight of a D800 body, compared with a D7000 body ...
     Your comparisons of the 2010 Nikon D7000 to the 2012 Nikon D800, with roughly equal pixel size, might be relevant to your particular gear ownership, but not to this thread's main topic of "comparing micro four thirds to full frame" or to the far more common situation of the larger format having larger pixels, and this requiring longer focal lengths to get an equally detailed image of a subject. (Typically about 1.4x longer in the Four Thirds to 36x24mm comparison.) So I will leave that one and return to the main topic.

... if you consider that 16mp is your minimum standard for all your purposes of future printing, cropping and display, then to get the same flexibility on an Olympus E-M5 as you could get on a Nikon D800, in relation to that required minimum pixel count of 16mp, the lens on the Olympus 4/3rds that would be fully equivalent to a standard 50mm/F2.8 lens on the D800, would need to be a 25-50mm/F1.4 zoom.
You have a strange fascination with comparing that case of a 50mm prime and use of larger apertures (low f-stops) to what would be needed to reproduce it in a smaller format.  I instead am more interested in a portable kit offering a wide range of focal lengths well into the telephoto range, and so I ask with what I would replace my current light-weight walk-about wildlife lens, the 423g Olympus 75-300? Allowing for a 1.4x crop possible while matching pixel count, a lens for a Nikon FX body would need to cover about 150-420mm; there are lenses that roughly do so, but all are substantially heavier and more expensive. They are faster too of course, but so long as the 75-300 gets the job done for me, the extra bulk and cost does not attract me. If I did get more ambitious, I would look at the 985g Panasonic 100-400mm, covering roughly what would require 200-560mm in Nikon DX, so the 2,300g Nikon 200-500 is the closest I see.

Your comparison and mine both make sense, according to different photographic goals. The difference illustrates a general trend: that larger format advantages are most often realized at shorter focal lengths, while smaller format advantages are most noticeable towards the "long and narrow" end (also including macro, where I love my 60mm/2.8, always used at high f-stops except for focusing of course).

However, I agree we haven't really got full equivalence in this comparison because there are other advantages to a wider aperture, apart from a shallower DoF. One can use a faster shutter speed to freeze movement, and/or use a lower ISO setting in poor light, which can improve image quality.
Indeed, and that was all included in my two previous discussions of the low f-stop scenario, which includes using larger aperture sizes (larger entrance pupil diameter: focal length divide by aperture ratio) to get higher shutter speeds or less noise at the same shutter speed — this being inexorably tied (for better or for worse) to less DOF. Indeed, it seems to me that the main historic reason for using large apertures was to get adequate shutter speed with moving subjects (or shaky hand-held cameras!), with reduced DOF more often a price to be paid for that speed rather than an advantage in itself.
Title: Re: comparing micro four thirds to full frame
Post by: Ray on February 19, 2018, 02:09:53 am
Ray,
You have a strange fascination with comparing that case of a 50mm prime and use of larger apertures (low f-stops) to what would be needed to reproduce it in a smaller format.  I instead am more interested in a portable kit offering a wide range of focal lengths well into the telephoto range, and so I ask with what I would replace my current light-weight walk-about wildlife lens, the 423g Olympus 75-300? Allowing for a 1.4x crop possible while matching pixel count, a lens for a Nikon FX body would need to cover about 150-420mm; there are lenses that roughly do so, but all are substantially heavier and more expensive. They are faster too of course, but so long as the 75-300 gets the job done for me, the extra bulk and cost does not attract me. If I did get more ambitious, I would look at the 985g Panasonic 100-400mm, covering roughly what would require 200-560mm in Nikon DX, so the 2,300g Nikon 200-500 is the closest I see.


BJL,
I've merely used the example of the 50mm lens in order to make the comparison simple. In fact, I have a general preference for zoom lenses, because of their flexibility, and a general preference for high pixel-count cameras because the lens quality of the zooms is effectively upgraded as one downsamples the images in accordance with whatever purpose one requires for the image.

Let's upgrade to the Nikon D850, which is 45mp. To get a 16mp image would require no more than a 1.7x crop. In terms of a minimum 16mp image size, the popular Nikkor 80-400/F4.5-F5.6 zoom, which I happen to use a lot, becomes the equivalent of an 47-680 zoom, in relation to your E-M5 with 75-300 lens (which is equivalent to a 150-600 zoom on full frame).

To get a Nikkor zoom lens for the D850, equivalent to the Olympus 75-300 with no pixel-count disadvantage, it would need to be a 127-353 lens. There's no such lens. The closest is the Sigma AF 70-300mm f/4-5.6 DG OS (FX), which weighs 610 grams, or just 187 grams heavier than the Olympus 75-300. Not a big deal for me.

One of the benefits of that extra weight is a much wider lens at one end. However, the slightly shorter focal length at the long end, 510mm instead of 600, can be compensated through a reduction of pixel count, from 16mp to 11 mp. No big deal.
The less wide angle of the Olympus zoom (150mm FF equivalent, compared with the 70mm of the Sigma zoom) cannot always be compensated. When needing to capture the moment, when the subject is moving, stitching might not work. You might lose the best shot you ever had the opportunity to take.  :D

In addition to those advantages of the Sigma zoom at the wide end, there are other significant advantages. At certain specific focal lengths of both lenses, from 70-300mm on the D850, and from 75-176mm on the E-M5, the D850 will produce a significantly better image in all respects. Even if you consider 45mp to be overkill and unnecessary for the prints you might want to make, when those 45mp images are downsampled to 16mp, the resolution and low noise will beat any results you could get from the finest Olympus prime lenses available.

That more expensive and slightly heavier D850 body has effectively converted a $400 Sigma zoom, and all of one's other zoom lenses, into a huge range of top notch prime lenses (or at least decent quality prime lenses), in relation to the smaller 16mp sensor of the E-M5. Wow!  ;D

And all this for a total weight increase of just 677 grams, including body and zoom lens.

Hope I've got my calculations right.  ;)
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 19, 2018, 07:19:49 am
Try again with one of the 20 MP MFT bodies, restoring the 1.4x focal length factor. Actually, a better comparison is an entire kit, so how about my two lens dream of Olympus 12-100 and Panasonic 100-400. There is probably about a 500g difference in camera body weights, and I am for now ignoring the price gap.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 19, 2018, 08:36:10 am
Try again with one of the 20 MP MFT bodies, restoring the 1.4x focal length factor. Actually, a better comparison is an entire kit, so how about my two lens dream of Olympus 12-100 and Panasonic 100-400. There is probably about a 500g difference in camera body weights, and I am for now ignoring the price gap.

Which camera are you referring to? The 20mp Olympus Pen-F? And why use a 1.4x focal length factor?

The Nikon DX format has a 1.5x focal length factor; the Canon cropped format a 1.6x focal length factor, and the Micro 4/3rds a 2x focal length factor, comparing the long side of the frame. Comparing the height of the 4/3rd's frame with the height of the full frame 35mm format, the focal length factor is 1.8x.

I just checked the DXOmark graphs, comparing the 20mp Pen-F with the D850 at the pixel level. At the lower base ISO of the D850, the D850 pixel has almost 4dB better SNR at 18%, which translates to smoother skin tones in portraits.

DR at the pixel level is almost a whopping 2 stops better at the lower base ISO. At ISO 200 the DR advantage drops to about 1.5 stops, which is still very significant. At the nominal 400 ISO for the Pen-F, and at all higher ISOs, the DR of the D850 pixel is still one full stop better, after adjusting for differences in the actual ISO sensitivities. Refer attached image.

Need I go on?  ;D


Title: Re: comparining micro four thirds to full frame
Post by: SrMi on February 19, 2018, 11:52:00 am
Which camera are you referring to? The 20mp Olympus Pen-F? And why use a 1.4x focal length factor?
 <snip>
Need I go on?  ;D

The best 20mp m43 sensor is in OM-D E-M1mII not in Pen-F (and probably also in Lumix G9, but there is no data about it yet). Interestingly, if you compare dynamic range of X1D, D850, and E-M1mII on DXOmark (https://www.dxomark.com/Cameras/Compare/Side-by-side/Olympus-OM-D-E-M1-Mark-II-versus-Hasselblad-X1D-50c-versus-Nikon-D810___1136_1114_963), you'll see that there is more difference between X1D and D850 than between D850 and M1mII. Of course, that graph is not the only relevant one.
Title: Re: comparining micro four thirds to full frame
Post by: Telecaster on February 19, 2018, 04:56:23 pm
I use my m43 gear mostly for travel, where its small size and weight are big advantages. A small shoulder bag carries the lot of it, and sails easily through airport checkpoints. In use the camera and lenses attract no notice. Real-world image quality differences between a Panasonic GX8 and a Sony A7rii are, for my travel needs and purposes (YMMV), small enough to not matter. Really!

I use my larger format gear mostly with fast lenses shot wide open or nearly so. This is where it has an advantage for me. If for some reason I felt the urge to use 35mm format gear with lenses at ~f/8, after a second thought I'd likely opt for m43 at ~f/4 instead.

-Dave-
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 19, 2018, 08:25:05 pm
Ray,
    I was referring to any of the six MFT bodies with 20MP sensors, from either Olympus or Panasonic.

The 1.4x factor is how much longer lenses on the D850 need to be in order for a 20MP crop to cover the same field of view as on such a MFT body. The same as for the previous 16MP vs 36MP comparisons.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 19, 2018, 08:31:11 pm
I use my m43 gear mostly for travel, where its small size and weight are big advantages. A small shoulder bag carries the lot of it, and sails easily through airport checkpoints. In use the camera and lenses attract no notice. Real-world image quality differences between a Panasonic GX8 and a Sony A7rii are, for my travel needs and purposes (YMMV), small enough to not matter. Really!

I use my larger format gear mostly with fast lenses shot wide open or nearly so. This is where it has an advantage for me. If for some reason I felt the urge to use 35mm format gear with lenses at ~f/8, after a second thought I'd likely opt for m43 at ~f/4 instead.

-Dave-

Fair enough! Whatever satifies you and suits your purpose is the best option.  Most of my photography is done during my travels, so I'm reluctant to compromise the degree of quality that I'm used to, for the sake of a kilogram, or so, less weight. I actually go through the baggage check with my D810 and 14-24 zoom slung around my neck so it's not included in the weight of my carry-on luggage. I've never been asked to weigh the camera that's around my neck.  ;D

However, I can see the advantages of a lighter system, obviously. A few years ago I bought the Panasonic Lumix FZ200, which has a very impressive, fixed, 25-600mm/F2.8 lens attached. I wondered if this camera would satisfy me, regards image quality. I spent a lot of time comparing the image quality with equivalent focal lengths from my Canon and Nikon DSLRs, and it became clear that the Panasonic was no match, so I sold it to a neighbour.

There is also another issue which might tend to be glossed over. Whilst the image quality at the long end of an MFT zoom might compare very favourably with the significantly cropped image from a full-frame lens, the purpose of a zoom is to provide a number of different focal lengths to use, without the need to change lenses. The image quality from those wider focal lengths, from the D850 for example, will tend to be significantly better.

Let's take the example of one of BJL's dream lenses, the Panasonic 100-400, which becomes a very impressive 200-800 in full-frame equivalence. The closest equivalent zoom on the D850, to get the same reach, might be the Sigma 150-500, about 800 grams heavier.

A 1.6x crop at 500mm results in a 17.5mp image at 800mm equivalence. The resolution from the 20mp Micro 4/3rds should be better, because of the significant crop of the Sigma lens at 500mm. The difference in pixel count is insignificant, but the difference in DR will still favour the Sigma/D850 image.

The over all impression might be that the Panasonic image at 400mm is at least slightly better. It would be interesting to see real world comparisons.

However, what are the quality differences at wider focal lengths with each zoom? At all focal lengths between 100 and 250mm with the Panasonic lens, the comparison will be between 20mp and 45mp. Downsampling the 45mp image to 20mp, for the sake of a sensible comparison, the image from the D850 becomes significantly better in all respects.

The DR advantage at the lower base ISO becomes 2.5 EV. Even at ISO 200, the DR is a full 2 stops better. At all other ISO's the D850 image is around 1.5 stops better (compared with the Pen-F).

At the pixel level, the greater SNR (at 18%) is only noticeable at the lower ISO of the D850. However, when the image is downsampled to 20mp, that SNR advantage becomes much more significant. At the lower base ISO of the D850, it's about 7.1dB better, and about 5dB better at all other ISOs.

https://www.dxomark.com/Cameras/Compare/Side-by-side/Nikon-D850-versus-Olympus-PEN-F___1177_1070

Color sensitivity and tonal range are also noticeably better. I would expect resolution also to be better, even if the Sigma zoom is of lower quality than the Panasonic.


Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 19, 2018, 08:36:14 pm
Ray,
    I was referring to any of the six MFT bodies with 20MP sensors, from either Olympus or Panasonic.

The 1.4x factor is how much longer lenses on the D850 need to be in order for a 20MP crop to cover the same field of view as on such a MFT body. The same as for the previous 16MP vs 36MP comparisons.

BJL,
The angle of view has nothing to do with pixel count. If the sensors have a different pixel pitch, equal angles of view, or equal fields of view, will unavoidably consist of a different number of pixels, in all circumstances, at the same focal length equivalence.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 19, 2018, 09:02:08 pm
The best 20mp m43 sensor is in OM-D E-M1mII not in Pen-F (and probably also in Lumix G9, but there is no data about it yet). Interestingly, if you compare dynamic range of X1D, D850, and E-M1mII on DXOmark (https://www.dxomark.com/Cameras/Compare/Side-by-side/Olympus-OM-D-E-M1-Mark-II-versus-Hasselblad-X1D-50c-versus-Nikon-D810___1136_1114_963), you'll see that there is more difference between X1D and D850 than between D850 and M1mII. Of course, that graph is not the only relevant one.

Thanks,
I don't keep track of all the developments in Micro 4/3rds format, so I just did a search on 20mp MFT cameras and the Pen-F came up first. I'll check the DXOMark results for the OM-D E-M1 mll.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 19, 2018, 09:34:32 pm
Okay! I've chacked the DXO results for the OM-D E-M1 MkII, and the DR and SNR are better than the Pen-F. However, the advantages of the Sigma 150-500 zoom on the D850 are still significant, and I presume still very noticeable.

Between the focal lengths of 100 to 250 on the Panasonic zoom lens, equivalent to 200 to 500 on the Sigma/D850 without cropping, the increased DR at the lower base ISO of the D850, has fallen to a mere 2 stop advantage. At other ISO's the advantage is sometimes as little as 1 full stop.  ;)

SNR is only around 6.3dB better, at base ISO. At all other 'equal' ISOs it's between 3 and 4dB better. Still noticeable. Resolution of the downsampled image has to be better, unless that Sigma zoom is a crap lens.
Title: Re: comparining micro four thirds to full frame
Post by: SrMi on February 19, 2018, 09:43:21 pm
Thanks,
I don't keep track of all the developments in Micro 4/3rds format, so I just did a search on 20mp MFT cameras and the Pen-F came up first. I'll check the DXOMark results for the OM-D E-M1 mll.

Yes, m43 has made quite a jump forward with M1m2 and G9. I prefer using photonstophotos to DXOMark:

http://www.photonstophotos.net/Charts/DXOPDR.htm#Nikon%20D850,Olympus%20OM-D%20E-M1%20Mark%20II (http://www.photonstophotos.net/Charts/DXOPDR.htm#Nikon%20D850,Olympus%20OM-D%20E-M1%20Mark%20II)

Of interest may be also the dynamic range graph for the high res mode of M1m2, which shows similar dynamic range as D810/D850:

http://www.photonstophotos.net/Charts/PDR_HighResShotMode.htm#Olympus%20OM-D%20E-M1%20Mark%20II(HR) (http://www.photonstophotos.net/Charts/PDR_HighResShotMode.htm#Olympus%20OM-D%20E-M1%20Mark%20II(HR))

Knowing the limitations and possibilities of m43 is crucial to extracting best image quality from the camera.

Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 19, 2018, 10:08:32 pm
The angle of view has nothing to do with pixel count. If the sensors have a different pixel pitch, equal angles of view, or equal fields of view, will unavoidably consist of a different number of pixels, in all circumstances, at the same focal length equivalence.
Ray, I think I do not explain myself clearly enough. I am talking about the fact that you have referred to in other ways: when a 36x24mm format body has pixel pitch 1.4x larger than a MFT body, matching both the FOV and pixel count in the larger body is possible with only 1.4x times the focal length if one is willing to crop to the pixel count of the smaller format sensor, not the full 2x times the focal length. For example, to match the FOV options that I get at 16MP with my diminutive 211g 12-50 lens and 425g EM5 body, I might not need a 24-100mm lens on a D800, but only a 24-70. Though in this case, the 485g 24-85/3.5-4.5 would be a closer match than the 1070g 24-70/2.8 in comparison the far smaller and slower 12-50/3.5-6.3. But even then, with the D8xx bodies all weighing 980g or up (slightly less than my standard kit of EM5 + 12-50 + 75-300) the Nikon kit would be far heavier, so some very big trade-offs in both directions.

By the way, you never got back to me about a proposed Nikon kit to match my dream kit of 20MP MFT body with 12-100 and 100-400 lenses. (I am guessing that there will be a 20MP EM5 Mk III this year, but as I mentioned above, there are six other 20MP MFT options; for those somewhat bigger lenses, the EM1 Mk II with its deeper handgrip might be the best fit, despite its whopping 574g.)

P. S. Please remember that I am not aspiring to match what your kit can do; in the spirit of the OP, the question is whether the IQ advantages of a larger format kit are, for my purposes, sufficient to justify that bulkier and more expensive kit. For example, I have not been bothered by insufficient DR when using the EM5 at base ISO speed, so the attraction of even more base ISO speed DR is a bit like the attraction of replacing a 200 kph car by a 300 kph one with far worse fuel economy.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 20, 2018, 12:27:49 am
Ray, I think I do not explain myself clearly enough.

BJL,
You are still not explaining yourself clearly enough. If one is using equivalent prime lenses with two different formats which have a different pixel pitch, the pixel count will inevitably be different. Adjusting the crop factor in order to equalize the pixel count causes the 'field of view' to be different. Downsizing or upsizing doesn't change the field of view.

Field of view always takes precedence over pixel count. All of my hundreds of thousands of images taken over the years, are all cropped to a specific angle of view, without exception. I would never allow pixel count to influence the composition of my images.
My first DSLR was the 6mp Canon D60. I would never think, "Oh! That fuzzy foreground needs cropping, but Hey! this will reduce the pixel count from 6mp to 4mp. Maybe I shouldn't crop."  :D

Quote
By the way, you never got back to me about a proposed Nikon kit to match my dream kit of 20MP MFT body with 12-100 and 100-400 lenses.

Easy. The Nikkor 24-120/F4 plus the Sigma 150-500. The gap between 120mm and 150mm is easily fixed with just a slight cropping of the D850 image at 120mm. The resulting pixel count and image quality would still be better than the equivalent 20mp MFT format quality between 120 and 150mm.
Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on February 20, 2018, 03:31:40 am
The DR advantage at the lower base ISO becomes 2.5 EV. Even at ISO 200, the DR is a full 2 stops better. At all other ISO's the D850 image is around 1.5 stops better (compared with the Pen-F).
(...)

Ray, are you aware that DR or ISO (noise in general) differences, are becoming negligible with time? do you understand that a difference of 2,5 stops in DR between cameras with 11 and 13,5 stops of DR has not the same real world effect as the same 2,5 stops between those cameras with 8 and 10,5 stops of DR we used to have years ago?. Real scenes are not increasing their dynamic range, typical poorly lit scenes are not becoming more poorly lit with time. This means that while technology improves the advantages in noise of larger sensors are vanishing in practical terms.

I am an engineer and I love numbers and measurements, but I think you are losing the real world usage perspective. I have a FF camera with the only purpose of easily obtaining shallow DOF when I want to (something that can be enjoyed even at web size), and to adapt legacy 35mm lenses at cheap prices. Noise and DR stopped being a problem with my M4/3 years ago, by the time Olympus began to use Sony sensors (http://www.guillermoluijk.com/misc/rd_olympus.png).

Regards
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 20, 2018, 07:33:26 am
Ray, are you aware that DR or ISO (noise in general) differences, are becoming negligible with time?

Guillermo,
You're sounding like someone who has sacrificed DR capability for other features which you find more attractive or useful, and are therefore in a state of denial about the benefits of what you've sacrificed.  ;)

I do realize that DR issues have become less of a problem as the DR capability of cameras in general has increased. When I was using the Canon 5D and Canon 50D on a regular basis, I used to bracket almost all shots automatically because I was so fed up with the sight of unpleasant noise in the shadows when I processed the images on the computer. Those were also the days, because of limited DR, when ETTR processes were a bit of an obsession. If DR is a problem, then underexposing by half a stop makes the problem worse.

Now that I use Nikon cameras, which usually have the best DR available, I feel free of any obsessions with ETTR and the need to bracket exposures in case there is noise in the shadows.

Quote
Do you understand that a difference of 2,5 stops in DR between cameras with 11 and 13,5 stops of DR has not the same real world effect as 2,5 stops between a couple cameras with 8 and 10,5 stops we used to have years ago?.

Do you understand that people often use higher-than-base ISOs, such as ISO 400, 800 and 1600 and that the DR at these ISOs is sometimes as bad as the DR at the base ISO in older cameras?

The attached DXOMark graph shows a difference of at least one full stop in DR at all ISOs from 200 to 3200, comparing the D850 with the Olympus OM-D E-M1 MkII. Do you remember the days when people got so excited when the first Nikon full-frame DSLR (the D3) had a 1/2 stop better DR than the best Canon models, at high ISOs? The Nikon D3 still has 1/2 a stop better DR than the OM-D E-M1, at the nominal ISO of 800. But not at other ISOs, so you can relax.  ;D

Quote
Real world scenes are not increasing their dynamic range, typical poorly lit scenes are not becoming more poorly lit with time. This means that the advantages in noise of larger sensors are vanishing in practical terms.

I think you are underestimating the full dynamic range of many scenes, as the eye perceives them. The eye is continuously adjusting to the lighting conditions as it peruses a scene. A simple example would be a shot of one's living room which takes in the view of a sky and landscape, with bright clouds, through a large window.

Without additional lighting in the living room, or the bracketing of exposures, there would probably be lots of noise in the photographic shot of the living room, or a blown sky. However, the eye when perusing such a scene, sees no such noise because it is in effect doing its own bracketing. As the gaze shifts to the bright clouds, the eye's pupils narrow in diameter. When the gaze shifts to details in the living room, the pupil widens and the eye takes in more light. It's estimated this process, which is very quick, gives the human eye a dynamic range capability of about 20 stops.

Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on February 20, 2018, 08:05:57 am
I do realize that DR issues have become less of a problem as the DR capability of cameras in general has increased.

Indeed, this is the only thing you needed to say to confirm that you understand that the differences in DR/ISO FF vs M4/3 are becoming irrelevant in practice Ray, and will continue to do so. Thanks.
Title: Re: comparining micro four thirds to full frame
Post by: hogloff on February 20, 2018, 09:46:23 am
Indeed, this is the only thing you needed to say to confirm that you understand that the differences in DR/ISO FF vs M4/3 are becoming irrelevant in practice Ray, and will continue to do so. Thanks.

Well if for your type of photography DR is becoming irrelevant...then that's great for you. Others might shoot different types of scenes where DR, even with the top performing cameras, is still a challenge. Your generalization is based on your experience, not others.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 20, 2018, 09:54:40 am
Indeed, this is the only thing you needed to say to confirm that you understand that the differences in DR/ISO FF vs M4/3 are becoming irrelevant in practice Ray, and will continue to do so. Thanks.

No. You misunderstand me. When one is aware of the DR limitations of one's equipment, one tends to avoid certain subjects, or perhaps blacken the shadows instead of revealing noisy detail. Better DR allows one to tackle new types of scenes and perhaps be more innovative.

I agree with Hogloff in this respect.
Title: Re: comparining micro four thirds to full frame
Post by: NancyP on February 20, 2018, 11:05:26 am
All this is to say that you can't cheat Ma Physics.  ::)

Larger format telephoto lenses (refractors) of equivalent field of view and equivalent f/ are....larger, and being made of glass, significantly heavier.
Larger format lenses have less depth of field at equivalent field of view and equivalent f/. This is either an advantage or disadvantage, depending on your subject. Non-photo-gear-obsessed insect and other macro-subject naturalists often like the depth of field advantage of point-and-shoot cameras, as well as their convenience in the field.
Larger pixels will accommodate more photons, therefore, noise can be lower, color accuracy potentially higher, dynamic range higher, other things being equal. (Fantasy wish: full pixel dump and re-zeroing in real time, at least for some lower shutter speeds).
Larger format cameras are....larger, and generally heavier. I like the handling of a "prosumer"-size DSLR, the Canon 6D being an example, it fits my hand, the dinky Rebels feel slightly "crowded". On the other hand, I grew up with a much smaller film SLR camera, and liked its handling at that time. Conspicuousness might be a concern with larger cameras (street and PJ, travel in areas with lots of thieves, etc).




Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on February 20, 2018, 12:16:50 pm
Well if for your type of photography DR is becoming irrelevant...then that's great for you. Others might shoot different types of scenes where DR, even with the top performing cameras, is still a challenge. Your generalization is based on your experience, not others.

If for your type of photography DR is fundamental, but your M4/3 has 20 stops of DR vs 22,5 stops in the FF, both cameras would be identically capable of capturing ANY real world scene. If sensors have more and more DR on every yearly iteration, there will be less and less real world scenes where FF will make any difference vs M4/3, so the "FF has more DR" story is becoming more and more irrelevant year after year. That is what I’m trying to expose.

According to DxOMark, two shots on my 2005 Canon 350D 4EV apart capture more DR than a single shot on a Nikon D850 at ISO64.

Regards
Title: Re: comparining micro four thirds to full frame
Post by: hogloff on February 20, 2018, 02:54:12 pm
If for your type of photography DR is fundamental, but your M4/3 has 20 stops of DR vs 22,5 stops in the FF, both cameras would be identically capable of capturing ANY real world scene. If sensors have more and more DR on every yearly iteration, there will be less and less real world scenes where FF will make any difference vs M4/3, so the "FF has more DR" story is becoming more and more irrelevant year after year. That is what I’m trying to expose.

According to DxOMark, two shots on my 2005 Canon 350D 4EV apart capture more DR than a single shot on a Nikon D850 at ISO64.

Regards

Sure...when we reach that 20 stops of DR...yes it will become irrelevant...but until then...it is relevant. Very much like high ISO noise reaching levels where it becomes irrelevant...but until that time...it too is still relevant.
Title: Re: comparining micro four thirds to full frame
Post by: Telecaster on February 20, 2018, 03:32:05 pm
My general observation is that the less real-world relevant a particular spec or feature becomes, the more emphatic people become in their insistence upon its continued relevance.   :)  Just wait 'til we're comparing Camera System A with 24.9 stops of usable DR at ISO 102800 to Camera System B with 24.8 stops of same at same. There will be wars fought over this.

-Dave-
Title: Re: comparining micro four thirds to full frame
Post by: hogloff on February 20, 2018, 04:00:56 pm
My general observation is that the less real-world relevant a particular spec or feature becomes, the more emphatic people become in their insistence upon its continued relevance.   :)  Just wait 'til we're comparing Camera System A with 24.9 stops of usable DR at ISO 102800 to Camera System B with 24.8 stops of same at same. There will be wars fought over this.

-Dave-

What are these “less real world relevant” specs that you are talking about?
Title: comparing micro four thirds to full frame
Post by: BJL on February 20, 2018, 07:24:49 pm
BJL,
You are still not explaining yourself clearly enough. If one is using equivalent prime lenses with two different formats which have a different pixel pitch, the pixel count will inevitably be different. Adjusting the crop factor in order to equalize the pixel count causes the 'field of view' to be different. Downsizing or upsizing doesn't change the field of view.
Ray, I am not talking about equivalent prime lenses: I am not sure where you get that idea; the lenses that I have mentioned are a 12-50, 75-300, 12-100 and 100-400 zooms. My point is the simple fact (of which you are aware, as you have referred to it in other posts) that when a larger sensor with more pixels and pixel pitch 1.4x larger, getting the same pixel count on the same subject [the same angular resolution] require forming an image at the focal plane that is about 1.4x larger (linear), and so using a focal length 1.4x longer, and then cropping as needed (or using a longer focal length and so forming an even larger image, and then downsampling).

For example to match the telephoto reach of the long end of the Olympus 12-100mm on a 20MP MFT body like the EM1 Mk II would, on a D850, need at least 140mm, cropped to match FOV, and to match the long end of the Panasonic 100-400mm would require at least 560mm.

That said, your proposed matching of that 12-100 and 10-400 by a Nikon 24-120 plus [discontinued] Sigma 150-500 is close but falls a bit short: some combination like 24-140 and 200-560 would be needed. At the long end, one option I see is the Sigma 150-600/5-6.3 DG OS HSM | C.

Some weight comparisons:

Olympus 12-100/4   561 g
vs
Nikon 24-120/4      710 g
    Just a bit heaver and "shorter" in reach.

Panasonic 100-400/4-6.3            985 g, $1800. C.f. 200-560
vs
Sigma 150-500/5-6.3               1780 g
    A lot heaver and a bit shorter in reach.
or
Sigma 150-600/5-6.3 DG OS HSM | C      1930 g
    Even heaver, with a bit more reach.

As Nancy points out, Physics allows no free lunch in either direction: a larger sensor with more and larger photosites, paired with bigger, heaver (and usually more expensive) lenses can given results that look better under some circumstances.


P. S. Note that the EM1 Mk II has a pixel shifting high resolution mode matching about 40MP [Correction: about 50MP; I was thinking the EM5 Mk II], so if and when that can be used (tripod, good enough lens resolution, etc.) we are back fairly close to straight focal length equivalents, so needing a pair of F-mount lenses covering 24mm to about 800mm.

Title: Re: comparining micro four thirds to full frame
Post by: armand on February 20, 2018, 09:23:29 pm
This feels like deja-vu.
Here are more weights and thoughts:
http://forum.luminous-landscape.com/index.php?topic=110045.0
http://forum.luminous-landscape.com/index.php?topic=102175.0
Title: Re: comparining micro four thirds to full frame
Post by: kers on February 21, 2018, 05:20:58 am
According to DxOMark, two shots on my 2005 Canon 350D 4EV apart capture more DR than a single shot on a Nikon D850 at ISO64.
Regards
I often need 3 shots of a d850 2EV apart...  ( there were times in the low-DR-past i needed to blend 5 to even 7 exposures)
2 ev apart because the blending is done more easy...

+ would not want to miss the large prism viewfinder- one reason i would not go to dx format.
Title: Re: comparing micro four thirds to full frame
Post by: Ray on February 21, 2018, 06:46:36 am
Ray, I am not talking about equivalent prime lenses: I am not sure where you get that idea; the lenses that I have mentioned are a 12-50, 75-300, 12-100 and 100-400 zooms. My point is the simple fact (of which you are aware, as you have referred to it in other posts) that when a larger sensor with more pixels and pixel pitch 1.4x larger, getting the same pixel count on the same subject [the same angular resolution] require forming an image at the focal plane that is about 1.4x larger (linear), and so using a focal length 1.4x longer, and then cropping as needed (or using a longer focal length and so forming an even larger image, and then downsampling).

For example to match the telephoto reach of the long end of the Olympus 12-100mm on a 20MP MFT body like the EM1 Mk II would, on a D850, need at least 140mm, cropped to match FOV, and to match the long end of the Panasonic 100-400mm would require at least 560mm.

That said, your proposed matching of that 12-100 and 10-400 by a Nikon 24-120 plus [discontinued] Sigma 150-500 is close but falls a bit short: some combination like 24-140 and 200-560 would be needed. At the long end, one option I see is the Sigma 150-600/5-6.3 DG OS HSM | C.

Some weight comparisons:

Olympus 12-100/4   561 g
vs
Nikon 24-120/4      710 g
    Just a bit heaver and "shorter" in reach.

Panasonic 100-400/4-6.3            985 g, $1800. C.f. 200-560
vs
Sigma 150-500/5-6.3               1780 g
    A lot heaver and a bit shorter in reach.
or
Sigma 150-600/5-6.3 DG OS HSM | C      1930 g
    Even heaver, with a bit more reach.


Okay! I get your point, BJL. In order to ensure that the D850 does not have a resolution disadvantage at the long end of the equivalent zoom, we need to use a longer focal lenth so that we need to crop the D850 image less, getting the same FOV whilst simultaneously achieving at least an equal pixel count of 20mp in both images.

That of course does increase the combined weight of the D850 system. I didn't know the Sigma 150-500 had been discontinued. If we use the Sigma 150-600 instead, the additional weight is only 150 grams. At 600mm, the D850 image, after cropping to the same FOV as the uncropped 400mm image from the EM1 MkII, would have more than 20mp, and each of those pixels is of better quality than the EM1 MkII pixel.

Lens quality issues are also a factor. It would be interesting to see a real-world comparison between the two lenses at the long end, on the different bodies. There might not be much difference at the long end but there sure will be at shorter focal lengths when the D850 doesn't need to be cropped at all, or might need to be be cropped only slightly to get the same FOV.

Adding up the weights of all these lenses and bodies, the 24-120 and 150-600 with the D850, and the 12-100 and 100-400 with the E-M1 MkII, the combined weights are; 2.12 Kgs for the MFT system, and 3.55 Kgs for the 35mm system.
That's an extra 1.43 Kgs for all the benefits of the much larger sensor with much higher pixel count most of the time when using zoom lenses, and better pixel quality.

As I understand, the main argument in favour of the Olympus 4/3rds system is that it provides sufficient image quality for your purposes, with an over all saving in weight and size, and therefore greater convenience of use. I can appreciate that.

If I were taking up digital photography as a new hobby, I would definitely consider opting for the Olympus 4/3rds system, now that they have a 20mp sensor with reasonably good quality pixels. However, in my current circumstances, already owning several Canon and Nikkor lenses, I would not be prepared to switch systems, unless the new system had no disadvantages, and only advantages.

Quote
P. S. Note that the EM1 Mk II has a pixel shifting high resolution mode matching about 40MP [Correction: about 50MP; I was thinking the EM5 Mk II], so if and when that can be used (tripod, good enough lens resolution, etc.) we are back fairly close to straight focal length equivalents, so needing a pair of F-mount lenses covering 24mm to about 800mm.

This is an interesting development. However, one way that I reduce the weight of my camera system nowadays, for the sake of convenience and the reduction of a lot of messing around, is not to bother with tripods anymore, unless they are really essential for a particular type of effect, such as the blurring of the water in a waterfall or taking shots at night, or in very poor light.

My impression is that pixel shifting requires a very stable tripod to avoid the slightest movement. Stable tripods tend to be heavy. That 1.43Kg of weight saving, which is the main justification for choosing the lighter MFT system, will be cancelled, will it not?  ;)

Also, pixel-shifting is only successful with static subjects, a bit like bracketing exposures for merging to HDR, so it's use is rather limited.

Have I made an irrefutable case?  ;D

P.S. Having done a bit of investigation on the pixel-shift feature of the E-M1 MkII, I'm getting the impression that the higher resolution is only significant when exceptionally good prime lenses are used. 90% of all lenses don't make the grade.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 21, 2018, 07:59:58 am
There's another factor which seems to be overlooked by the 'DR-benefit deniers'.  ;)
Let's say one camera in the comparison has a DR of 13 EV, and the other camera has a DR of 10 EV, using the same standards of analysis.

Some folks might argue that 10 stops of DR is quite sufficient for their purposes. However, it's not necesarily the case that both cameras will produce acceptably good detail and low noise in those parts of the image which are at the sensors' DR limit.

The real advantage in practice, of the camera with 13 EV of DR, is that those parts of the scene that are underexposed by 10 EV, or 9 EV or 8EV will tend to be cleaner and more detailed than the same parts of the scene shot with the camera with a DR limit of only 10 EV.

Noise is something which increases gradually in accordance with the different degrees of light levels in the different parts of the scene.

The concept of PDR (Photographic Dynamic Range) attempts to address this issue, although I still prefer the engineering results shown in the DXOMark graphs because the comparisons are so easy to see, and cover so many different models of cameras, at both the pixel level and at a downsampled standard which allows comparison of the entire sensor.

I've actually taken the trouble to do my own tests, so I know just how deteriorated the image looks at the engineering DR limit of the camera, but I also know how much better the image looks from the camera with a DR limit of 13EV, when the image, underexposed by 9 stops, is compared with the same scene from a camera with a DR limit of 10EV, when that image is also underexposed by 9 stops.

Hope that's not too confusing.  ;)
Title: Re: comparining micro four thirds to full frame
Post by: HSakols on February 21, 2018, 10:00:28 am
This has been an interesting discussion.  Ray, I hope I haven't been too snarky. I'm no engineer and I'm kind of playing devils advocate because I'm trying to understand the real world differences.  Over the long weekend I only used my Olympus because I had to climb 4300 ft. in 7 miles to get to where I wanted to photograph. Yes, I would have liked a full frame, but I can no longer carry one that far.
Title: Re: comparining micro four thirds to full frame
Post by: Slobodan Blagojevic on February 21, 2018, 10:08:06 am
Ray, in relation to the graph below, I think what proponents of m4/3 are saying is this: if you have to achieve the same DOF, you'd have to double the ISO on a full-frame camera, therefore shifting the Nikon line to the left, bringing it closer to the Olympus one. No?
Title: Re: comparining micro four thirds to full frame
Post by: hogloff on February 21, 2018, 11:37:10 am
Ray, in relation to the graph below, I think what proponents of m4/3 are saying is this: if you have to achieve the same DOF, you'd have to double the ISO on a full-frame camera, therefore shifting the Nikon line to the left, bringing it closer to the Olympus one. No?

Why would one have to double the ISO. Most of my landscape images are taken at base ISO.
Title: Re: comparining micro four thirds to full frame
Post by: Slobodan Blagojevic on February 21, 2018, 12:08:45 pm
Why would one have to double the ISO...

That's not even a serious question, but I'll repeat what I said in the above post: "to achieve the same DOF."
Title: Re: comparining micro four thirds to full frame
Post by: NancyP on February 21, 2018, 12:40:28 pm
Do what you need to do to get the photograph you want. Not the photograph someone else says is "ideal" (unless you are a pro selling that photo), the photo YOU want.

Be grateful you aren't Curtis dragging around mules carrying glass plates and a portable darkroom through Southwest canyons.  :o
Of course, there are modern Curtis types driving truck-cameras... https://www.kickstarter.com/projects/1376821505/invisible-light-the-dolomites-in-ultra-large-forma (no endorsement - just a google search for "large format truck camera")
Title: Re: comparining micro four thirds to full frame
Post by: armand on February 21, 2018, 02:20:31 pm
Why would one have to double the ISO. Most of my landscape images are taken at base ISO.

That's not even a serious question, but I'll repeat what I said in the above post: "to achieve the same DOF."

While less likely for the dedicated landscape photographers I've been in this situation multiple times while hiking. Many times you see different opportunities and on long trails you don't have time to keep messing with your tripod and you just shoot handheld. A good stabilization system and more DOF for the same ISO/aperture can be quite helpful.
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 21, 2018, 07:30:19 pm
Ray, in relation to the graph below, I think what proponents of m4/3 are saying is this: if you have to achieve the same DOF, you'd have to double the ISO on a full-frame camera, therefore shifting the Nikon line to the left, bringing it closer to the Olympus one. No?
That is true if you also need equal shutter speed (and it is a quadrupling of the exposure index (so-called ISO speed) if you want to make full use of the larger sensor rather than cropping to equal pixel count).

However if a longer exposure time is allowable, for example with a tripod or when there is enough light, then the larger format has the greatest potential for an IQ advantage. Then again, at base ISO speed, dynamic range is abundant for the vast majority of situations. Except for the modern day “14 Zone system” practitioners.

By the way, as I have explained many times, DXO uses a completely wrong ISO measurement when adjusting its horizontal axis: one based on highlight headroom rather one that compares at an equivalent level of exposure (equal Exposure Index), so its comparison rewards cameras that have the least headroom in their raw files at elevated ISO settings.  By DXO, a truly ISO-less camera with no need to use variable gain before ADC would always be at base-ISO regardless of its ISO setting!
Title: Re: comparining micro four thirds to full frame
Post by: Slobodan Blagojevic on February 21, 2018, 07:41:38 pm
That is true if you also need equal shutter speed ...

Indeed. But we are discussing a ceteris paribus situation, in other words, where all other elements stay the same, but you need more DOF, then you need to raise ISO.

If you are shooting action, street, even portraits, you can't lower the shutter speed. Even if you use a tripod, there are situations where you do not want just any shutter speed. For instance, if you are shooting moving water, only a certain shutter speed will result in the effect that you want. Or if your scene contains moving objects (e.g., in landscape, moving leaves, or grass, even clouds). Also, there are certain shutter speeds that are less optimal than others, even when on tripod (something to do with shutter bounce).
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 21, 2018, 07:44:35 pm
Ray, in relation to the graph below, I think what proponents of m4/3 are saying is this: if you have to achieve the same DOF, you'd have to double the ISO on a full-frame camera, therefore shifting the Nikon line to the left, bringing it closer to the Olympus one. No?

Yes and No. It depends on the circumstances; the type of lens that is attached to the camera, whether it's a zoom or a prime; the lighting conditions, the quality of the image stabilization, and the relative pixel densities of the cameras being compared.

If lighting conditions were such that one could use the E-M1 MkII at its base ISO, at a minimum shutter speed for full sharpness, using a prime lens of equivalent focal length to the prime lens on the D850, then the D850 would need to be stopped down 2 stops and ISO raised 2 stops.

However, the DXOMark graph shows that the DR would be about the same for both cameras, or even slightly better for the D850, in those circumstance. At higher ISO's, when the conditions require the E-M1 to be used at, say, ISO 400, then the D850 would have to be used at ISO 1600, which would put it at a disadvantage of maybe 1/2 or 2/3rds EV of DR.

However, owners of the MFT systems would probably not consider this an advantage for them, because they don't care much about DR capability. It's generally so good nowadays that it's not an issue for them. Ask Guillermo.  ;D
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 21, 2018, 07:47:17 pm
Ray, you have made an irrefutable case that if I used a substantially bigger, heavier and more expensive Nikon 36x24mm format kit, I could sometimes get images that are measurably better in some “photographic engineering” sense, and better in ways that are significant to you. Without knowing my subject choices and display method or those of other MFT users in this thread, you cannot say more about how much we would benefit, or about how good or bad our MFT images look in practice.

 By the way, I was mostly joking about the high res. mode; I severely doubt it would work at the long end of a 100-400 zoom.

Also, since your graphs show that even the tiny pixels of the OMD EM1 Mk 2 give about 13 stops of DR, you might want to update that argument about why 10 stops might not be enough. I agree with the basic point that usable “photographic dynamic range” is several stops less than “engineering dynamic range”.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 21, 2018, 07:54:44 pm
Indeed. But we are discussing a ceteris paribus situation, in other words, where all other elements stay the same, but you need more DOF, then you need to raise ISO.

If you are shooting action, street, even portraits, you can't lower the shutter speed. Even if you use a tripod, there are situations where you do not want just any shutter speed. For instance, if you are shooting moving water, only a certain shutter speed will result in the effect that you want. Or if your scene contains moving objects (e.g., in landscape, moving leaves, or grass, even clouds). Also, there are certain shutter speeds that are less optimal than others, even when on tripod (something to do with shutter bounce).

Yes. It works both way, Slobodan. If one introduces the various types of scenes that require a specific shutter speed for a specific effect or a specific F/stop for a required DoF effect, then either camera system can be at an advantage or disadvantage. Guillermo apparently uses a 35mm full-frame system only for the advantage of its shallower DoF capability.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 21, 2018, 08:38:34 pm
Also, since your graphs show that even the tiny pixels of the OMD EM1 Mk 2 give about 13 stops of DR, you might want to update that argument about why 10 stops might not be enough. I agree with the basic point that usable “photographic dynamic range” is several stops less than “engineering dynamic range”.

BJL,
That's the point I've been making. Also, whilst 13 stops of engineering DR (or 10 stops of PDR) might be sufficient at base ISO for most circumstances, the DR is significantly reduced at higher ISOs. At ISO 1600, the engineering DR of the EM1 MkII is about 10 stops, maybe 7 stops PDR. The D850 is about 1 full stop better.

A  difference between 7 EV and 8 EV of 'real and useful' DR is surely significant, wouldn't you agree?

On the other hand, if one is using ISO 1600, it is because of the need for an adequate shutter speed, so the advantages and disadvantages of each system are then affected by the DoF requirements.

If I had the time, money and motivation, I could buy a complete MFT system and spend several days comparing the results with my Nikon system, under different circumstances. Who knows! I might prefer the latest MFT system with a 12-100 and 100-400 zoom.  ;)

Trouble is, I've already done that sort of thing in the past in order to reach my current situation with Nikon equipment. I'm not sure I want to go through all that obsessive trouble again.  ;D
Title: Re: comparining micro four thirds to full frame
Post by: LesPalenik on February 21, 2018, 11:01:12 pm
Another consideration is that the camera you have with you is always better than the camera you left home because it's too bulky and heavy. With my E-M1 and two zoom lenses I have a 24-600mm equiv range in a compact, lightweight kit. Can you imagine trying to get the same capabilities with FF gear?

Also worthy of thought are the newer "bridge" cameras with a 1" sensor, specifically the Sony RX10. There have been enormous strides in lens and sensor design and I am amazed at the image quality.

Peter,

Can you compare the image quality between Olympus and RX10? (especially on the long end).

Thanks,
Les
Title: Re: comparining micro four thirds to full frame
Post by: armand on February 21, 2018, 11:44:57 pm
Peter,

Can you compare the image quality between Olympus and RX10? (especially on the long end).

Thanks,
Les

Funny that you ask this as the advantages of m43 vs full frame can be applied to 1" vs m43. Question is when do we stop? When the sensor is to small?

For your question the RX10 will be however at some disadvantage at the long end as the lens is not that fast.
Title: Re: comparining micro four thirds to full frame
Post by: LesPalenik on February 22, 2018, 12:07:42 am
I'm interested primarily in the image quality. Lens speed is secondary.
On one hand the Sony RX10 sensor is only 1", compared with Olympus sensor, but if the Zeiss lens at 600mm is better than Zuiko 70-300 at 300mm, the resulting Sony image could beat the Four Thirds image. True or false?
   
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 22, 2018, 07:54:16 am
I also would like to see some comparisons. The Panasonic 100-400, with an effective 200-800mm range in terms of full-frame 35mm, does grab my interest because I do occasionally photograph birds and wildlife. (But I don't shoot them, of course.  ;D )

My longest lens is the AF-S Nikkor 80-400 F4.5-F5.6 G ED which I use with my D7100 or D5300. If my calculations are correct, when a 24mp DX sensor is cropped to the same size as a 4/3rds sensor, the pixel count is 14.8 mp. This is close enough to the 16mp of the EM5, but a bit far from the 20mp of the E-M1 MkII.

I would imagine that a lens designed for the MFT format should provide better resolution than a Nikkor FF lens that is heavily cropped. The extra megapixels, in combination with an effectively sharper lens, should result in a noticeably sharper and more detailed image.

I'd like to see a comparison to get an idea of just how much sharper the image is in practice, and how that extra sharpness at the long end of the zoom compares with the possible extra sharpness of a 24mp Nikon at wider focal lengths when cropping is not necessary, except to change aspect ratios.

The attached photo is of a group of Pelicans who are enthusiastically trumpeting the marvels of a Nikkor 80-400.  ;D

The image is cropped to a 4:3 aspect ratio for the benefit of the MFT fans.  ;)

Title: Re: comparining micro four thirds to full frame
Post by: Eric Myrvaagnes on February 22, 2018, 08:42:41 am
The attached photo is of a group of Pelicans who are enthusiastically trumpeting the marvels of a Nikkor 80-400.  ;D
Only two of the pelicans seem to be trumpeting. The rest are asleep.

And what about that little Canonbird in the lower left corner?   :D
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 22, 2018, 08:49:43 am
Only two of the pelicans seem to be trumpeting. The rest are asleep.

And what about that little Canonbird in the lower left corner?   :D

Oops! I should have written pair of pelicans. Glad you noticed the Canonbird.  ;D
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 22, 2018, 08:57:53 am
Also, whilst 13 stops of engineering DR (or 10 stops of PDR) might be sufficient at base ISO for most circumstances, the DR is significantly reduced at higher ISOs. At ISO 1600, the engineering DR of the EM1 MkII is about 10 stops, maybe 7 stops PDR. The D850 is about 1 full stop better.
...
On the other hand, if one is using ISO 1600, it is because of the need for an adequate shutter speed, so the advantages and disadvantages of each system are then affected by the DoF requirements.
The last point is the most important one: both for the sake of matching DOF and also due to the trend for [telephoto] lenses of longer focal lengths to have a higher minimum f-stop (or else to be heavier and more expensive in order to match f-stop), the comparison for many of us is more likely to be at equal effective aperture diameter: the larger format at an f-stop that is higher in proportion to the larger focal length used, and so at a higher EI in proportion to the square of focal length. Where a MFT camera would use 1600 ISO, a 35mm camera would likely use 6400 ISO if using the full frame, and maybe about 3200 ISO if cropped for equal resolution of the subject (equal pixel count.)

Once the DXO graphs are corrected to compare at equal EI (meaning more or less using the manufacturers stated EI values) the shadow noise and such are very close, maybe slightly favoring the smaller photosites according to some measurements I have seen. Which should be no surprise, since the two cameras would be gathering an equal among of light from the subject, so have equal photon shot noise, and if anything smaller photosites generate less electrons of dark/read noise.

If I had the time, money and motivation, I could buy a complete MFT system and spend several days comparing the results with my Nikon system, under different circumstances. Who knows! I might prefer the latest MFT system with a 12-100 and 100-400 zoom.  ;)
Don't bother: unless you are lying through your teeth in order to rationalize your gear choice, the advantages of your chosen format and brand outweigh the advantages of MFT, for your purposes.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 22, 2018, 09:02:33 am
This has been an interesting discussion.  Ray, I hope I haven't been too snarky. I'm no engineer and I'm kind of playing devils advocate because I'm trying to understand the real world differences.  Over the long weekend I only used my Olympus because I had to climb 4300 ft. in 7 miles to get to where I wanted to photograph. Yes, I would have liked a full frame, but I can no longer carry one that far.

Too snarky? Not at all. I'm sorry you are unable to bear the weight of a full-frame. How old are you, if you don't mind my asking?

A few years ago, at the age of 71, trekking along the Annapurna circuit in Nepal, I had to cross a pass in the mountains, the Thorong La Pass, at 17,770 feet (or 5416 meters). I carried with me the Nikon D800E, D7100, 80-400 zoom, 14-24/F2.8 zoom, 24-120/F4 zoom and tripod, with no problem.

Some of the gear was in my backpack, but around my neck I carried the D800E with 14-24 zoom, and D7100 with 24-120 zoom.
Here's a shot near the pass, at a height of maybe 5,000 meters.

However, I don't wish to appear as though I'm bragging. I did have a porter with me who carried my other stuff such as clothes, sleeping bag, laptop, charging devices, and so on.

Can you see the tiny trekkers in the foreground?
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 22, 2018, 09:42:42 am
Once the DXO graphs are corrected to compare at equal EI (meaning more or less using the manufacturers stated EI values) the shadow noise and such are very close, maybe slightly favoring the smaller photosites according to some measurements I have seen. Which should be no surprise, since the two cameras would be gathering an equal among of light from the subject, so have equal photon shot noise, and if anything smaller photosites generate less electrons of dark/read noise.

BJL,
All my comments on DR differences are based upon an estimate by imagining a vertical line from the lower DR figure to the higher DR figure on the graph. I believe photon shot noise, or SNR at 18%, has to vary by 3dB or more before it's of any real significance.

Quote
Don't bother: unless you are lying through your teeth in order to rationalize your gear choice, the advantages of your chosen format and brand outweigh the advantages of MFT, for your purposes.

I never lie, at least not consciously, unless I'm deliberately flattering someone.  ;)

I'm always open to the benefits of new gear. When I accidentally smashed my D800E on holiday in Thailand in 2015, which was the only camera I was carrying because it was a brief visit, I bought a D5300 with a DX 18-140 zoom at the local camera shop, so I could continue taking photos. I would have preferred a D7200, but they didn't have one in stock.

That D5300 with 18-140 zoom lens is remarkably light, but the main disadvantage is image quality, particularly at the edges and corners. If Nikon were to produce a really high quality 18-140 DX lens of similar weight, I would buy it, even at triple the price, and I would also upgrade to a D7200.
Title: Re: comparining micro four thirds to full frame
Post by: LesPalenik on February 22, 2018, 09:48:02 am

That D5300 with 18-140 zoom lens is remarkably light, but the main disadvantage is image quality, particularly at the edges and corners. If Nikon were to produce a really high quality 18-140 DX lens of similar weight, I would buy it, even at triple the price, and I would also upgrade to a D7200.

Triple price would buy Sony RX10iv, and possibly the image quality would be better with the Zeiss lens.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 22, 2018, 11:53:24 am
Triple price would buy Sony RX10iv, and possibly the image quality would be better with the Zeiss lens.

Maybe so, but a D7200 can be used with all my other Nikkor lenses. I also prefer OVF. A Panasonic 12-100 plus 100-400 covers almost the entire range that I normal use, but I wouldn't be satisfied if I had to sacrifice image quality at certain focal lengths in the zoom where the DX or FX format didn't need cropping, or needed very little cropping. No point in taking two steps forward and 2 steps backward.
Title: comparing micro four thirds to full frame—and 1” format
Post by: BJL on February 22, 2018, 02:25:55 pm
Funny that you ask this as the advantages of m43 vs full frame can be applied to 1" vs m43. Question is when do we stop? When the sensor is to small?

For your question the RX10 will be however at some disadvantage at the long end as the lens is not that fast.
The same trade-offs exist up and down the sensor size line, and I can see 1” being the best for some. Especially if in a larger format, you are using all slowish lenses to keep bulk and cost down. Likewise, APS-C format is the sweet spot for a lot of people, helped in part by the substantial price jump from there to a 35mm format body (comparing entry level options in each system, not the highest spec APS-C body to the cheapest in 35mm).

However, it seems that 1” format is being abandoned for ILC systems. Still, for someone who mostly uses a larger format but then wants a long telephoto option, a 1” format super-zoom all-in-one camera might be better than either a 4/3”  body with one long lens, or adding a long but very slow zoom lens to a 35mm format system.
Title: Re: comparining micro four thirds to full frame
Post by: Telecaster on February 22, 2018, 03:17:16 pm
This pic (attached) showed me again that m43 has the best size/performance tradeoff for my wants & needs when it comes to handholdable reach. On multi-day hiking trips I've often had the opportunity to take such a pic, but never the appropriate gear as I like traveling light. I could do better with 24mp APS-C & a stabilized 600mm lens, but the size & weight would be a burden. A Pany GX8/100–400mm combo is just compact enough and is easily handholdable for long periods.

-Dave-
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 22, 2018, 07:00:42 pm
All my comments on DR differences are based upon an estimate by imagining a vertical line from the lower DR figure to the higher DR figure on the graph. I believe photon shot noise, or SNR at 18%, has to vary by 3dB or more before it's of any real significance.
UPDATE 2: reading more st DXO, I am confused about how they measure the upper end of the DR, which is a strange that ng to care about when the sensor is greatly underexposed. I will try a new analysis tomorrow!

Which would make sense, except that DXO badly mangles the horizontal positioning of the data points, by confusing a measure of "highlight headroom after analog amplification into the raw file" with a measure of how much exposure the sensor is getting: Exposure Index, which is what is needed for low-light handling comparisons. To fix this, from what I recall reading, it is sufficient to use the EI values reported by the camera camera maker. Here are some from https://www.dxomark.com/Cameras/Compare/Side-by-side/Nikon-D850-versus-Olympus-OM-D-E-M1-Mark-II___1177_1136


UPDATE: Here, I originally used the "print" data, with DR scaled up to estimate the effect of downsampling to 8MP. Below I have added a comparison based on "screen" data, looking at raw pixel results. That shifts the comparison in favor of the EM1Mk2 sensor.


Olympus OMD EM1 Mk 2 dynamic range ("print" measurement)
pixel pitch 3.36 microns

EI=200 ISO: 12.84
EI=400 ISO: 12.68
EI=800 ISO: 11.9
EI=1600 ISO: 11.05
EI=3200 ISO: 10.37
EI=6400 ISO: 9.34
EI=12800 ISO: 8.81
EI=25600 ISO: 7.6

Nikon D850 dynamic range ("print" measurement)
pixel pitch 4.35 microns

EI=100 ISO: 14.61
EI=200 ISO: 13.97
EI=400 ISO: 13.37
EI=800 ISO: 12.59
EI=1600 ISO: 11.63
EI=3200 ISO: 10.79
EI=6400 ISO: 9.82
EI=12800 ISO: 8.84
EI=25600 ISO: 7.86
EI=51200 ISO: 6.87

Allowing for comparisons at equal DOF and equal pixel count, the D850 would be about one stop faster, so doubling EI. More precisely, the pixel pitch ratio is only 1.3, so this comparison is slightly biased against the D850; I think that theory suggests a difference of about log2((1.4/1.3)^2) = 0.21 stops.

EM1Mk2 @ 200: 12.84; D850 @ 400: 13.37      +0.53
EM1Mk2 @ 400: 12.68; D850 @ 800: 12.59      -0.09
EM1Mk2 @ 800: 11.9; D850 @ 1600: 11.63      -0.27
EM1Mk2 @ 1600: 11.06; D850 @ 3200: 10.79   -0.27
EM1Mk2 @ 3200: 10.37; D850 @ 6400: 9.83   -0.54
EM1Mk2 @ 6400: 9.34; D850 @ 12800: 8.84   -0.50
EM1Mk2 @ 12800: 8.84; D850 @ 25600: 7.86   -0.98
EM1Mk2 @ 25600: 7.6; D850 @ 51200: 6.87   -0.73

So the D850 has a moderate advantage at low EI, and more so when its lower EI values of 32 to 200 can be used, but then the gap goes the other way — but probably within the errors of this data and my crude comparison and in most cases below the visible threshold.

I would call it a tie as far as visible differences at moderately high exposure index.


UPDATE: using "screen" instead of "print":

Olympus OMD EM1 Mk 2 ("screen" measurement)
EI=200 ISO: 12.14
EI=400 ISO: 12.0
EI=800 ISO: 11.22
EI=1600 ISO: 10.37
EI=3200 ISO: 9.69
EI=6400 ISO: 8.66
EI=12800 ISO: 8.13
EI=25600 ISO: 6.92

Nikon D850 ("screen" measurement)
EI=32 ISO: 13.55
EI=100 ISO: 13.35
EI=200 ISO: 12.72
EI=400 ISO: 12.11
EI=800 ISO: 11.33
EI=1600 ISO: 10.37
EI=3200 ISO: 9.53
EI=6400 ISO: 8.56
EI=12800 ISO: 7.58
EI=25600 ISO: 6.6
EI=51200 ISO: 5.62

EM1Mk2 @ 200 > D850 @ 400 by 0.03
EM1Mk2 @ 400 > D850 @ 800 by 0.67
EM1Mk2 @ 800 > D850 @ 1600 by 0.85
EM1Mk2 @ 1600 > D850 @ 3200 by 0.84
EM1Mk2 @ 3200 > D850 @ 6400 by 1.13
EM1Mk2 @ 6400 > D850 @ 12800 by 1.08
EM1Mk2 @ 12800 > D850 @ 25600 by 1.53
EM1Mk2 @ 25600 > D850 @ 51200 by 1.30
Title: Re: comparining micro four thirds to full frame
Post by: HSakols on February 22, 2018, 08:08:13 pm
Quote
Too snarky? Not at all. I'm sorry you are unable to bear the weight of a full-frame. How old are you, if you don't mind my asking?

Ray, I'm in my early 50's and still love to backpack in Yosemite's wilderness.  Backpacking doesn't create better photos but it is something I have to do to stay inspired and stay in shape.  I enjoy it!  When I drive the Yosemite Valley loop I take my D800 with a hefty tripod - it's my 8x10 camera!

Here is another from Monday morning.  And yes I use a tripod for every shot just as I would with a larger format. It forces me to compose better. 

 
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 23, 2018, 07:59:04 am
Ray, I'm in my early 50's and still love to backpack in Yosemite's wilderness.  Backpacking doesn't create better photos but it is something I have to do to stay inspired and stay in shape.  I enjoy it!  When I drive the Yosemite Valley loop I take my D800 with a hefty tripod - it's my 8x10 camera!

Here is another from Monday morning.  And yes I use a tripod for every shot just as I would with a larger format. It forces me to compose better.

Nice shot, Hugh! At least you have some trees amongst the snow. At 17,000 feet in Nepal it's a bit more rugged, as the attached, stitched panorama shows, taken with the Nikon D7100 and 24-120/F4 zoom in 2013.

When zooming in on the panorama, I was surprised to see another couple of trekkers who appear to be emerging out of the snow, waist deep. I don't recall noticing that before. I've made a 100% crop which shows that additional couple in the lower left hand corner of the crop. Perhaps it's a perspective quirk.  ;)

Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 23, 2018, 08:30:40 am
Which would make sense, except that DXO badly mangles the horizontal positioning of the data points, by confusing a measure of "highlight headroom after analog amplification into the raw file" with a measure of how much exposure the sensor is getting: Exposure Index, which is what is needed for low-light handling comparisons. To fix this, from what I recall reading, it is sufficient to use the EI values reported by the camera camera maker. Here are some from https://www.dxomark.com/Cameras/Compare/Side-by-side/Nikon-D850-versus-Olympus-OM-D-E-M1-Mark-II___1177_1136

This is getting complicated, BJL. Perhaps the topic deserves another thread.  If you distrust the DXOMark results, then please do your own real-world comparisons and demonstrate to us how those qualified scientists employed by DXO are confused.

As I understand, the concept of 'highlight headroom' is only relevant for people who use the auto-exposure feature of their camera and don't take the trouble to get a proper ETTR exposure.

For example, consider a case of identical sensors in two different brands of camera. Both sensors could have exatly the same DR, but the different manufacturers who  design the cameras will supply different features to appeal to different customers. Changing the nominated ISO sensitivity, as it relates the camera's automatic metering system, will affect the so-called 'highlight headroom'.

I suspect that Olympus is capitalizing on the increased DR of its new cameras by encouraging underexposures so there will be fewer incidents of blown highlights. Here's a good explanation of the issue that I came across on the internet.

"As tests show, the ISO settings reported by camera manufacturers can differ significantly from measured ISO in RAW. This difference stems from design choices, in particular the choice to keep some “headroom” to avoid saturation in the higher exposures to make it possible to recover from blown highlights."

"Suppose you have a camera with a 12 stop exposure range. You can set the middle gray aim point at Zone 6, which gives you six stops of highlight and six stops of shadow range. Or you could decide that you're more concerned about highlights blowing out than anything else and set the aim point at Zone 5, which gives you an extra stop of highlight range but also a little more noise. Or you could go the other way and set the aim point at Zone 7, which gives you more shadow detail and lower noise but increases the risk of blown out highlights."


As I understand, the correct, or precise way to compare the DR figures on the DXO graphs is to draw a vertical line which intersects the two graphs. When the manufacturers' claimed ISO sensitivities are different, the vertical line will pass through only one DR reading. However, the value of the other reading can be easily estimated, and in practice, if you are doing comparisons with the actual cameras and lenses, the lower ISO should be increased, as far as possible, by 1/3rd ISO intervals, or whatever increments are available, till it reaches the higher actual ISO of the other camera, or if you prefer, the higher ISO should be reduced to match the lower.

For example, lets consider the DR reading for the E-M1 MkII at the manufacturer's claimed ISO of 1600, which is actually ISO 688 according to DXO. The DR reading is 10.37 EV. Drawing a vertical line from the ISO 1600 point, the line intersects with the D850 curve at approximately 1/3rd of an ISO beyond the Nikon nominated ISO of 800 (which is actually ISO 563). Increasing the D850's ISO by 1/3rd would make the camera's ISO reading ISO 1000, or actually ISO 703, which is close enough to ISO 688.

To compare the two cameras at this ISO setting, the E-M1 should be set at ISO 1600 and the D850 at ISO 1000. If the different lenses used at the same F/stop and same equivalent ISO seem to require different shutter speeds for an ETTR exposure of both images, then the likely cause is that the transmission of the lenses, or T-stop, is different.

A crucial point when attempting to do your own comparisons, is to make sure you are starting from a correct ETTR exposure which fully saturates, but not over-saturates, the pixels that are recording the brightest part of the scene. One then successively reduces the exposure by increasing the shutter speed by the same percentage for both cameras, keeping the ISO constant, and comparing the image quality at each reduction of exposure.

At ISO 1000 on the D850, which is approximately the same nominal sensitivity as ISO 1600 on the E-M1, the DR of the D850 pixel is at about 2/3rds of a stop better. The line intersects just above the 11 EV point.

If we compare the full sensors, downsized to a common standard, the DR advantage of the D850, at the actual ISO of 703 is about 1.3 EV better. Refer attached images of the two scenarios.

If you think this approach is wrong, then please provide real-world tests to demonstrate it is wrong. My acceptance of the accuracy of the DXOMark results is based upon my own testing.



Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 23, 2018, 08:56:31 am
Ray, as I said in my update, there is probably another correction needed, which moves the comparison in favour of the D850, and the new “screen” graph will help.No time to post it all now; hopefully later today!
Title: Re: comparining micro four thirds to full frame
Post by: HSakols on February 23, 2018, 10:32:34 am
Quote
Nice shot, Hugh! At least you have some trees amongst the snow. At 17,000 feet in Nepal it's a bit more rugged, as the attached, stitched panorama shows, taken with the Nikon D7100 and 24-120/F4 zoom in 2013.

When zooming in on the panorama, I was surprised to see another couple of trekkers who appear to be emerging out of the snow, waist deep. I don't recall noticing that before. I've made a 100% crop which shows that additional couple in the lower left hand corner of the crop. Perhaps it's a perspective quirk.  ;)

Wow! that second crop is strange. 
My wife and I just went to a presentation on trekking through Nepal by author Jon Bock. I look forward to spending some time there when I stop working full time, not only for the landscape, but for the culture and people. 
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 23, 2018, 02:25:22 pm
Ray, as I said in my update, there is probably another correction needed, which moves the comparison in favour of the D850, and the new “screen” graph will help.No time to post it all now; hopefully later today!
To follow up briefly: in addition to moving points right to their stated EI values 200, 400, etc., the extra highlight headroom given by those lower  raw level placements are probably counted in DXO’s total DR, but give nothing in terms of shadow handling, so to measure that (“shadow DR”) the points should then be lowered by as many stops as they are moved rightward. These roughly cancel, putting the curves in about the same places, so for now I will just use the curves as they are.

For per pixel comparisons (e.g. cropping to 20MP with the D850) the focal length ratio needed is 1.3, so about 3/4 stop higher EI on the D850: EM1Mk2 at 800 vs D850 at 1360 and so on. In other words, slide the D850 “screen” curve 3/4 stop left, or measure the horizontal spacing and see how the gap compares to 3/4 stop. Eye-balling it, it is close, with the EM1 edging ahead at extreme high EI; higher than I ever use.

If instead the full sensor is used and then downsampling to equal “print resolution” is assumed, then the “print” graphs can be used, and the focal length factor is two, so the D850 is compared at four times the EI: a two stop horizontal shift. The comparison looks about the same as above.
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 23, 2018, 02:42:43 pm
P. S. Those DXO measures of saturation based ISO speed simply show that everyone, Olympus more than some others, under-amplify when producing high EI raw files, in the sense of not bringing the nominal mid-tone level for that EI up to the minimum headroom level allowed by the ISO standard. Presumably, extra digital amplification in conversion from raw to JPEG is then indicated. It is nothing to do with exposure levels received by the sensor.

For example, some older CCD cameras like the Olympus E-1 simply capped analog gain at EI 1600: going to EI 3200 and halving exposure time halved the raw levels, so in DXO terms it was 1600 at all the higher levels. Newer near “ISO-less” sensors can benefit from something similar, reducing or eliminating analog gain, and thus adding highlight headroom with no significant damage to noise levels.
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 23, 2018, 08:58:59 pm
This pic (attached) showed me again that m43 has the best size/performance tradeoff for my wants & needs when it comes to handholdable reach. ...
That’s impressive! I’m sure you would love to have been this guy:
https://arstechnica.com/science/2018/02/amateur-astronomer-tries-out-new-camera-catches-supernova-at-its-start/
Title: Re: comparining micro four thirds to full frame
Post by: Telecaster on February 23, 2018, 10:31:09 pm
That’s impressive! I’m sure you would love to have been this guy:
https://arstechnica.com/science/2018/02/amateur-astronomer-tries-out-new-camera-catches-supernova-at-its-start/

Yeah, I heard about that! I'd need a little more aperture than what I've got to get in on that action.  :)

-Dave-
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 24, 2018, 04:31:01 am
P. S. Those DXO measures of saturation based ISO speed simply show that everyone, Olympus more than some others, under-amplify when producing high EI raw files, in the sense of not bringing the nominal mid-tone level for that EI up to the minimum headroom level allowed by the ISO standard. Presumably, extra digital amplification in conversion from raw to JPEG is then indicated. It is nothing to do with exposure levels received by the sensor.

It's everything to do with the exposure levels received by the sensor. Underexposure at any ISO results in more noise and less DR. Regardless of how accurate the manufacturer's nominated ISO's are in relation to the ISO standard, the same principle applies. A valid comparison between two cameras must always be at the same DXO-measured ISO sensitivity, which means raising or lowering the ISO of one of the cameras to match the other.

If Olympus is under-amplifying when producing RAW files at high ISO, that should be no problem for those who shoot in RAW mode and who understand the need for an ETTR exposure to achieve the maximum DR and the lowest noise. I always shoot in RAW mode.

I consider myself to be a practical person. I'm concerned with actual, real-world, results. In an imaginary world where all camera designs gave one the choices of only Field of View and Depth of Field, and the selection of shutter speed and F/stop was done automatically in-camera, according to the camera's light meter and according to a DoF index which one could select by turning a wheel with one's thumb, then the E-M1 MkII would have a consistent advantage over the D850, except for shallow DoF requirements.

In the real world, we use tripods when slow shutter speeds are needed. The lighting conditions tend to be so variable that quite often the shutter speed selected is far faster than it need be for a sharp, hand-held shot, and is selected only to avoid overexposure.

Nevertheless, I admit that a 20mp E-M1 MkII, in certain circumstances, should have a clear advantage in image quality, which is why I'd like to see some real-world comparisons. I'd be particularly interested in seeing a comparison between the E-M1 with 200mm lens, and both the Nikon D850 and D7200 with 400mm lens, because I already own a Nikkor 80-400, which I'm very pleased with, and am currently undecided whether to upgrade to a D850, and/or a D7200. My D5300 is seriously disadvantaged because it doesn't have an AF fine tuning feature, which is why I'm considering a D7200 upgrade. The D7200 also has approximately 2/3rds of a stop better DR than the D5300, from base ISO up to ISO 800 (nominal).
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 24, 2018, 05:30:41 am
Wow! that second crop is strange. 
My wife and I just went to a presentation on trekking through Nepal by author Jon Bock. I look forward to spending some time there when I stop working full time, not only for the landscape, but for the culture and people.

My association with Nepal goes back to 1964 when I was a backpacking hippie with a Pentax 35mm SLR and a couple of prime lenses. As a result of spending many hours in the 1990's scanning my old slides of shots I'd taken many years ago in Nepal, I was eventually motivated to revisit the country in 2005 with my new Canon 5D DSLR. I really enjoyed the experience and have revisited the country a number of times. The last time in 2013.

I haven't been to the country since the recent, devastating earthquake, because I think it would be too upsetting for me to witness the increased poverty and desperation of the common people. The only purpose would have been to help with the reconstruction process by contributing my own labour.

However, I expect they have now mostly recovered from the devastation, and tourism is on the rise again, especially Chinese tourism.  ;)

Pokhara is my favourite city destination. Unfortunately, Pokhara does not have an international airport yet, but they are planning or considering one. Kathmandu is a bit of a congested mess, but the mess is so extreme it becomes interesting because it's so amazing how people can live like that.

In some respects, visiting Nepal is like travelling in a time-capsule back to the Middle Ages in Europe. In the countryside, one often sees women sitting in front of a mound of freshly-harvested rice or corn, pounding and thrashing the rice with a long stick in their hands, just as one imagines people did in the Middle Ages.

Then suddenly the woman will stop thrashing the rice, lay her stick down, and reach into her pocket to grab an iPhone, have a conversation for the next few minutes, then resume her thrashing. (The correct term is threshing, but that's usually done with machinery, so 'thrashing' seems the better word in these circumstances.  ;D )

The first attached image was taken in 2006 when iPhones in the countryside were rare. The second image was taken in 2011.
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 24, 2018, 10:53:09 am
Ray, read DXO’s description of how they make those so-called ISO speed measurements and get back to me. You will see that the “lower than stated” values have nothing to do with the sensor being given less exposure (which would involve the camera using a higher shutter speed than selected!). It is instead based on measurements of raw file data after any gain (analog or digital) applied in pruducing those raw files. So you (and perhaps DXO) are ignoring the issue of how much gain is applied when at a high EI setting. Clearly, and for good reasons, most or all camera makers choose a gain level that places metered midtones below the highest level permitted by the ISO standard, for the sake of reducing the risk of amplifying highlights into clipping that were not blown out in the photo sites. Conversely, it would be folly for a camera to give less exposure than indicated by the EI setting, because it make the camera look worse in testing of noise levels.
Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 24, 2018, 11:13:58 am
Ray, “in the real world”, many of us have good reasons to prefer working hand-held most or all of the time so as not to carry a tripod—including places where tripods are not allowed. Indeed, this tends to be more the style of smaller format users, while tripod use tends to be more common with larger formats. I note also that hand-holding is vastly more doable with five stops or more of IS.

I completely agree with you that when using a tripod while photographing subjects that are stationary (or slowly enough moving and well enough lit), so that a sufficiently low shutter speed is always usable, the IQ advantages offered by a larger format are clear, at least when images are displayed large enough and scrutinised closely enough.

But wait: weren’t you comparing performance at elevated EI, which we agreed usually indicates a minimum shutter speed constraint based on subject motion, which would then be independent of format or tripod usage?

Indeed I get the feeling that one big factor in format size preferences is preferences and constraints on hand-holding vs tripod usage, and also the related preferences and constraints on kit weight.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 24, 2018, 10:45:07 pm
Ray, read DXO’s description of how they make those so-called ISO speed measurements and get back to me. You will see that the “lower than stated” values have nothing to do with the sensor being given less exposure (which would involve the camera using a higher shutter speed than selected!). It is instead based on measurements of raw file data after any gain (analog or digital) applied in pruducing those raw files. So you (and perhaps DXO) are ignoring the issue of how much gain is applied when at a high EI setting. Clearly, and for good reasons, most or all camera makers choose a gain level that places metered midtones below the highest level permitted by the ISO standard, for the sake of reducing the risk of amplifying highlights into clipping that were not blown out in the photo sites. Conversely, it would be folly for a camera to give less exposure than indicated by the EI setting, because it make the camera look worse in testing of noise levels.

BJL,
One of us seems very confused here. Perhaps it's me. As I understand, it's the internal processes of the camera that apply the gain at higher ISOs, in accordance with the manufacturer's design and decisions. We don't have a choice in the matter. Nor does DXO.

Pixel saturation, in at least a part of the sensor, is a required starting point to measure DR. At higher than base ISO, pixel saturation is achieved through in-camera amplification, not through the absorption of too many photons. This is why ISO-less, or ISO invariant cameras have an advantage. At fast shutter speeds, when one might normally raise the ISO setting, one can avoid using the camera's in-built amplification system, and do one's own amplification in Photoshop, thus removing the risk of blowing highlights, yet still maintain the same image quality as a correctly exposed shot at the usual higher ISO setting.

Unfortunately, Nikon DSLRs are not exactly ISO-invariant. There's usually a slight advantage in using the camera's in-built amplification, especially between base ISO and ISO 800. For example, if a camera is truly ISO-invariant then the drop in DR should be 3 EV when one uses ISO 800 instead of underexposing 3 stops at ISO 100.

However, with the D850, using the camera's amplification by choosing ISO 800, instead of using the same exposure at ISO 100, results in a drop in DR of only 2 stops. One gains a full stop of DR by using the ISO 800 setting on the D850. I find this type of information one can glean from the DXOMark graphs very useful in a practical sense.

Whilst many manufacturers over state their ISO settings, in relation to the ISO standards, most of them over state them by only 1/3rd to 2/3rds of a stop. Olympus over states the ISO sensitivity of the E-M1 MkII by over one full stop, approximately 1 & 1/4th of a stop. I see an element of marketing salesmanship here. By doing this the manufacturer is basically stating that their camera has an elevated ISO range at both the high end and low end, from ISO 200 to ISO 25,600. The actual range, according to the ISO standards, is from ISO 83 to ISO 10,916, approximately equal to ISO 100 to 12,800.

Do you see the deception? I've used cameras that have a base ISO of 200, such as the Nikon D700 full-frame, although the DXO-measured ISO was 158 which is approximately 1/3rd of a stop down, as is the case with most cameras (except Olympus, apparently).

I've found such cameras to be very advantageous for hand-held shots because at a real ISO of 158 (as opposed to a real ISO of, say 83, (which the E-M1 MkII has at base ISO), there is far less need to mess around changing the ISO settings back and forth. ISO 200 is useful for more conditions.

To advertise a camera as having a base ISO of 200, when in practice it is ISO 83, seems deceptive to me.
Now this leads on to the nub of the issue. At base ISO I presume that the camera's in-built software does not amplify the signal to compensate for the underexposure of the sensor that takes place as a matter of course at higher ISOs. Right?

If we were to compare a Nikon D700 and an Olympus E-M1 MkII, shooting the same scene, at the same nominated ISO of 200, with equivalent focal length lenses to give the same FoV, using the lenses at the same F/stop, and ensuring that the lenses had the same transmission or T-stop, would the shutter speeds be approximately the same for both cameras, if we were shooting in RAW mode and attempting to achieve an ETTR shot for maximum DR and the lowest noise?

That's the $64,000 question. Can you answer it JBL and dispel my confusion.  ;)

I am assuming that the E-M1 MkII, in those circumstance, at base ISO, which should involve no analogue amplification of the signal, will require approximately double the exposure of the D700 to get an ETTR shot in RAW mode.

I won't answer the other points you've made until I am clear about this issue. It would be really useful if someone reading this thread happens to own both a D700 and E-M1 Mk II and is prepared to do the comparison under the conditions I've described. However, an awareness of the T-stop factor is also essential for accurate and meaningful results.

Title: Re: comparining micro four thirds to full frame
Post by: BJL on February 26, 2018, 10:43:33 pm
BJL,
One of us seems very confused here. Perhaps it's me.
Yes, I am fairly sure it is you, gin the number of flatly incorrect statements in the rest of your post. I will try to dig up and refresh an old post that I made, explaining what DXO actually measures and what the ISO 12232:2006 standard actually says and does not say, but in summary:

- The ISO standard defines several measures of completely different aspects of camera performance (SSNR10 and SSNR40, SSat, SOS and REI); these are not just several ways of measuring the same thing, even though they use the same units of measurement. I will use the analogy that the focal length and the physical length of a lens are both measured in mm, but are not the same thing: their values are often similar, but can be wildly different as with some slow telephoto lenses and with extreme wide angle lenses.

- The "ISO" setting on a camera is for Exposure Index, relating to shutter speed at given film/sensor illumination conditions, as roughly described by "sunny 16" film speed description: "the shutter speed used to get correct exposure with standard development if the subject is an 18% gray card illuminated by bright sunshine and photographed at f/16".

- The SSat measure of highlight headroom is not in any sense a measure of Exposure Index, even if the values are typically similar; you (and maybe DXO) seems to confuse these two distinct concepts. Saying that a company is lying when the Exposure Index ("ISO" setting) differs significantly from the measured SSat is as totally wrong as saying that a lens maker is lying if the stated focal length of a lens is significantly different than its measured physical length.

- Likewise, there is no reason why the minimum Exposure Index setting should equal the sensor base-ISO speed. Instead, a guideline is that the SSat measure at a given EI setting should be at least a bit less than the EI value, to reduce the risk of blown/clipped highlights. Any EI setting less than the base ISO speed should be flagged as an "extended low" EI, to warn of its sub-standard highlight headroom and greater proneness to blown highlights. This is what Nikon does with its EI=32 setting, which according to DXO has SSat=44, the sensor's base ISO speed.

But you will have to wait for me to dig out my justification of these statements.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on February 27, 2018, 09:14:13 am
BJL,
Please don't misinterpret my use of the word 'deception' as lying. Deception is a normal part of every day life, amongst all creatures, not just humans. In Australia, lying in advertisements for products is illegal. Deception is not. There is a subtle difference which I'm sure you must be able to appreciate.

If in fact the E-M1 MkII produces an ETTR shot in RAW mode at ISO 200, at approximately the same shutter speed and F/stop as most other DSLRs at the ISO 200 setting, give or take 1/3rd of a stop, then I would consider DXOMark's rating of ISO sensitivity as being deceptive.

I'm not in the business of promoting any particular brand of camera. I'm concerned only with the facts.
I did a search for reviews of the Olympus E-M1 MkII, and it certainly has some impressive features, but my confusion about its base ISO remains.

Here are a couple of quotes from: http://www.ayton.id.au/wiki/doku.php?id=photo:olympusomdem1ii
and  http://www.ayton.id.au/wiki/doku.php?id=photo:olympusomdem1ii#fn__2

Issues
"ISO settings are more than 1EV higher than actual measured ISO and the LOW ISO of 64 was measured as being the same ISO as ISO 200 setting - that is, both equate with a true ISO of 83!"

"Strangely, the E-M1 II's ISO is actually around 1 stop higher than actual measured ISO except for the extended low ISO of 64 which is really ISO 83 and comparable to it's ISO 200 (the E-M1 I base ISO of 200 was measured at ISO 122, which was about the same as it's LOW ISO of 100) - so be careful when setting exposures manually based upon other camera's exposure settings!"


Even they seem to be confused.

I also did a search on the ISO Standard 12232:2006, and came across a paywall for the full pdf. However, I also came across the following comments from someone who appears to have read the full document.

"The ISO standard 12232:2006 gives digital still camera manufacturers a choice of five different techniques for determining the exposure index rating at each sensitivity setting provided by a particular camera model. Three of the techniques in ISO 12232:2006 are carried over from the 1998 version of the standard, while two new techniques allowing for measurement of JPEG output files are introduced from CIPA DC-004.

Depending on the technique selected, the exposure index rating can depend on the sensor sensitivity, the sensor noise, and the appearance of the resulting image. The standard specifies the measurement of light sensitivity of the entire digital camera system and not of individual components such as digital sensors, although Kodak has reported using a variation to characterize the sensitivity of two of their sensors in 2001."

"The Standard Output Specification (SOS) technique , also new in the 2006 version of the standard, effectively specifies that the average level in the sRGB image must be 18% gray plus or minus 1/3 stop when exposed per the EI with no exposure compensation . Because the output level is measured in the sRGB output from the camera, it is only applicable to sRGB images—typically JPEG—and not to output files in raw image format. It is not applicable when multi-zone metering is used.

The saturation-based technique is closely related to the SOS technique, with the sRGB output level being measured at 100% white rather than 18% gray. The saturation-based value is effectively 0.704 times the SOS value. Because the output level is measured in the sRGB output from the camera, it is only applicable to sRGB images—typically TIFF—and not to output files in raw image format. It is not applicable when multi-zone metering is used."

I look forward to any clarification you can provide on this issue, BJL.

Title: Re: comparining micro four thirds to full frame
Post by: BJL on March 04, 2018, 10:18:43 pm
I have mostly prepared a detailed discuss of what the Exposure Index setting on a camera is and is not about, but meanwhile, just one comment: the ISO standard like 12232:2006 do not define an quantity called the "ISO" or the "true ISO" of a camera; that is just casual, somewhat sloppy language, with "ISO" being used roughly as a synonym for Exposure Index. The ISO standards instead define measurements of several different quantities — and "SSat" is simply not the same thing as Exposure Index, "EI".

Thus when DXO says:

"ISO settings are more than 1EV higher than actual measured ISO and the LOW ISO of 64 was measured as being the same ISO as ISO 200 setting - that is, both equate with a true ISO of 83!"

it is literally nonsense, and reveals a mysterious sloppiness or ignorance, and even a touch of arrogance when it says "true ISO" without knowing the truth of what ISO standards actually say and mean.

More in a while!
Title: Re: comparining micro four thirds to full frame
Post by: Ray on March 05, 2018, 09:03:11 pm
I have mostly prepared a detailed discuss of what the Exposure Index setting on a camera is and is not about, but meanwhile, just one comment: the ISO standard like 12232:2006 do not define an quantity called the "ISO" or the "true ISO" of a camera; that is just casual, somewhat sloppy language, with "ISO" being used roughly as a synonym for Exposure Index. The ISO standards instead define measurements of several different quantities — and "SSat" is simply not the same thing as Exposure Index, "EI".

Thus when DXO says:

"ISO settings are more than 1EV higher than actual measured ISO and the LOW ISO of 64 was measured as being the same ISO as ISO 200 setting - that is, both equate with a true ISO of 83!"

it is literally nonsense, and reveals a mysterious sloppiness or ignorance, and even a touch of arrogance when it says "true ISO" without knowing the truth of what ISO standards actually say and mean.

More in a while!

Don't worry about it, BJL. DXOMark measurements are relevant only for those who shoot in RAW mode and who are concerned about achieving an ETTR exposure most of the time. I believe most people who use DSLRs shoot in Jpeg mode and are quite happy to let the camera do most of the image processing, in accordance with their own selection for the appropriate scene.

One could argue endlessly whether or not DXO's interpretation of the ISO standard is technically correct and strictly conforms to the letter of the standard.

For me, the only issue is the consistency of DXO's measurements and their practical significance.

For example, if at the nominated ISO of 200, Camera A has a DXO-measured ISO of 83, and Camera B has a DXO-measured ISO of 130, then camera A should require about 2/3rds of a stop more exposure than camera B, (ie. slower shutter speed), to achieve  an ETTR exposure with minimum noise.

This is the only issue for me, and this issue can only be resolved with practical experiments comparing ETTR shots at the same f/stop, same T-stop, and same equivalent focal lengths, and by making exposure adjustments if the T-stops differ.

There is also the point to consider that Guillermo made. As DR improves generally, as camera technology progresses, DR becomes less of an issue. It certainly has for Guillermo, but he used to be a fanatic about DR, even promoting a procedure known as UniWB to extract slightly more DR from an image by avoiding the clipping of perhaps just one color that could result from a camera-selected white balance.

I was never that fanatical.  ;D
Title: Re: comparining micro four thirds to full frame
Post by: NancyP on March 06, 2018, 01:57:28 pm
Somewhat off topic:

While people are gram-counting, it might be worth thinking about how you carry that equipment. Gram counting may be essential for peak-bagging or through-hiking, less essential for day hikes and weekend hikes. A good pack and carriage system makes a huge difference in how the weight feels. Photo-specific packs don't fit me, even the high quality brands such as F stop. I have a short torso length (15") and need a women's extra-small or small size pack with a properly fitting shoulder harness and properly fitting hip belt. I use an ordinary panel-loading hiker's pack with a camera insert, and may also use the Cotton Carrier vest with it for instant camera access. 20 pounds of gear feels like "nothing" when not dealing with significant elevations.

Anxiously awaiting next weekend, to give my new Mystery Ranch Cairn 32 L (women-specific design) pack a spin with full kit in F stop insert (medium and large inserts fit). Best panel access yet.
Title: Re: comparining micro four thirds to full frame
Post by: BJL on March 06, 2018, 10:08:17 pm
DXOMark measurements are relevant only for those who shoot in RAW mode and who are concerned about achieving an ETTR exposure most of the time.
Ray, can you define EXPOSE To The Right [ETTR] and explain why — with your definition — an ETTR exposure is relevant in "low light" situations where the exposure index needed well above the "base ISO speed"? (Which by the way is a nickname for what ISO 12232 defines as SSat, the basis for DXO's "true ISO".)

I ask because my understanding of the virtue of EXPOSING To The Right is about choosing the maximizing sensor EXPOSURE level that avoids blown highlights due to over-filled photosites. That is, pushing the histogram of photo-electron counts in photosites as far to the right as possible. This is desirable if it can be done, because that maximized sensor exposure maximizes SNR levels and so minimizes visible noise in the final image.

If you are instead looking at histograms of raw levels after possibly different levels of analog gain have been applied, the connection between histogram placement and SNR levels is broken. As a hypothetical example, consider two cameras with identical sensors: camera A could record a scene with a half stop more exposure than camera B [1/2 stop lower EI], but then amplify it one stop less (half as much) so placing the raw values half a stop lower (further from the right), so camera A would be worse by some "ETTR" criterion, but so long as the amplification in both cases raises the photon shot noise above the cameras' internally produced noise, camera A would give lower visible noise levels in the final image. (There is also the distinct possibility that the greater amplification on camera B causes highlight clipping that is avoided by camera A.)
Indeed, this could be done with the same camera, by choosing different combination of f-stop, shutter speed and EI setting ("ISO dial" setting): say 1/2 stop lower actual EI and one stop lower "ISO dial" setting.

But anyway, these comparisons with different exposure levels are mostly irrelevant for low light ("high ISO speed") photography with shutter speed constraints and such. In this situation, and assuming manual selection of shutter speed and aperture, the main questions for me are:
Once a minimum shutter speed is required and a maximum aperture size imposed by factors like the limits of available lenses or a minimum DOF requirement, and the result is underexposure of the sensor,

Q1) What "ISO dial" setting is best? Or at a more basic level, what is the best amount of analog gain to apply before ADC?

Q2) With these optimal settings, how are the noise levels?

The way that DXO does its testing, the needed "equal shutter speed at equal sensor illumination" comparison for that situation is given with equal on-camera "ISO dial" settings, not equal "DXO SSat" measurement.
Title: Re: comparining micro four thirds to full frame
Post by: BJL on March 06, 2018, 10:12:23 pm
There is also the point to consider that Guillermo made. As DR improves generally, as camera technology progresses, DR becomes less of an issue. It certainly has for Guillermo, but he used to be a fanatic about DR ...
Completely agreed! That is what I am actually more interested in measures of noise at various exposure levels than various attempts to define and then measure a photographically relevant flavor of "dynamic range". DXO's SNR 18% is a good start, if the horizontal axis is reinterpreted correctly.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on March 07, 2018, 09:18:12 am
While people are gram-counting, it might be worth thinking about how you carry that equipment. Gram counting may be essential for peak-bagging or through-hiking, less essential for day hikes and weekend hikes. A good pack and carriage system makes a huge difference in how the weight feels. Photo-specific packs don't fit me, even the high quality brands such as F stop. I have a short torso length (15") and need a women's extra-small or small size pack with a properly fitting shoulder harness and properly fitting hip belt. I use an ordinary panel-loading hiker's pack with a camera insert, and may also use the Cotton Carrier vest with it for instant camera access. 20 pounds of gear feels like "nothing" when not dealing with significant elevations.

Good points, Nancy. I don't have a problem with a short torso length, being 6ft tall, yet I still don't bother using my 'photo-specific' back pack with various cushioned compartments for camera bodies and lenses.

I sometimes tend to buy things because they seem a good idea at the time, then later discover there are certain inconveniences or awkwardness that make it not such a good idea. My photo-specific back pack has remained in the storage shed, unused for the past 15 years or so.

I always hike with a small and ordinary, lightweight, back pack, such as a cyclist might use on a push bike. I place some bubble-wrap material in the base of the back pack in case the bag is dropped to the ground too suddenly, perhaps damaging the equipment. The weight on my back tends to counter balance the weight of one of my cameras and lenses on my front.

Nevertheless, I can see the advantages of light equipment. I have a Nikon D5300 with Nikkor 18-140 zoom, which weighs in total just over 1Kg, roughly equivalent to an E-M1 MkII with 12-100 zoom.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on March 07, 2018, 09:28:35 am
Ray, can you define EXPOSE To The Right [ETTR] and explain why — with your definition — an ETTR exposure is relevant in "low light" situations where the exposure index needed well above the "base ISO speed"? (Which by the way is a nickname for what ISO 12232 defines as SSat, the basis for DXO's "true ISO".)

BJL,
As I've mentioned before, whatever the ISO setting, one can overexpose or underexpose. At higher than base ISO, the internal amplification of the signal is fixed in accordance with the ISO setting and the camera design. The photographer doesn't have any control over that degree of amplification in relation to a specific ISO setting.

Most cameras are not ISO invariant. An underexposure at any ISO results in an image with more noise than an ETTR shot at the same ISO. In other words, an ETTR at ISO 1600 will usually produce a better image than the same shutter speed used at ISO 800, except for truly ISO invariant cameras.

An ETTR shot is the maximum exposure, or the slowest shutter speed, that does not result in a loss of detail in the brightest part of the scene that one considers relevant to the composition.

That will generally exclude areas such as spectral highlights and small patches of sky visible through the leaves of a tree, or any bright patches which are devoid of detail or which one might consider to be less significant than the detail in the shadows of the scene.

There are various techniques of achieving an ETTR exposure. One method, which I tried years ago when using my Canon 5D, was to use a single focusing square in 'spot meter' mode, direct the square at the brightest part of the scene, such as the brightest part of the sky, take note of the shutter speed in the viewfinder, then manually reduce the shutter speed by 3 stops, or maybe it was 2.5 stops, can't remember. It's different for different models of camera.

Unfortunately, I found such a process  rather slow and cumbersome. It was quicker and easier to simply bracket exposures for all shots, +/- at least 1 EV, in auto-exposure mode, then choose the most appropriate shot in Photoshop's Camera RAW, which would usually be the shot which looked slightly overexposed before adjustments were made to retrieve highlight detail.

Now that I'm using Nikon equipment, I find it quicker and easier to use the AF-On button which separates both focusing and exposure from the shutter button. All I have to do is observe the exposure meter in the viewfinder as I swing the single focusing square to the brightest part of the scene, and adjust the shutter speed with my thumb.

The exposure meter has a zero in the centre, a minus sign at the extreme left, and a plus sign at the extreme right. With the focusing square covering the brightest part of the scene, I adjust the shutter speed so that the meter reading in the viewfinder is at the far right. Literally, an exposure to the right. No need to fuss around examining the histogram.


Title: Re: comparining micro four thirds to full frame
Post by: NancyP on March 07, 2018, 11:59:57 am
One other slightly off-topic item to consider is whether you tend to concentrate on one genre per photography outing, or several, and whether you are willing to forego some equipment options to save weight (or brain-space  :) ). At this point, I am day hiking mostly, and choose between birding-specific and landscape / macro options. I can get by with a traditional DSLR. The smaller format weight advantage shines when one is doing long-distance hiking or traveling, and one wants to have all options on hand.

One of my favorites for lightweight day hiking is the Canon 6D plus pancake 40mm f/2.8 - a PITA to manually focus (it is focus by wire), but this is really a nice landscape lens stopped down. I like the 35mm to 40mm angle of view in local wooded landscapes (hint, Canon or other - 35 mm tilt/shift?). I throw in a light macro lens (Voigtlander 125 mm) if I want to capture any incidental flora, fungi, or insects as well.

Light but good tripods are another issue. I have been happy with my full-size Feisol carbon fiber 4-section tripod CT-3442 plus an Arca-Swiss p0 head with  Sunwayfoto screw Arca-style QR clamp, total circa 2.8 pounds / 1.3 kg, for landscape / macro. However, with a smaller-format kit, I suppose that the really tiny "travel tripods" like the Sirui T025X (2 pounds with head) would be more than adequate.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on March 07, 2018, 07:43:37 pm
One other slightly off-topic item to consider is whether you tend to concentrate on one genre per photography outing, or several, and whether you are willing to forego some equipment options to save weight (or brain-space  :) ). At this point, I am day hiking mostly, and choose between birding-specific and landscape / macro options. I can get by with a traditional DSLR. The smaller format weight advantage shines when one is doing long-distance hiking or traveling, and one wants to have all options on hand.

True. I tend to be a peripatetic photographer, wandering from place to place where the unexpected scene can appear at any moment, whether the appearance of a beautiful landscape as the track bends around the corner, a Tibetan in traditional costume racing around the bend on a horse, or a flock of vultures in a nearby field feeding on some dead animal.

My ideal camera for such circumstances would be something like the DX Nikon D7200 with a really high quality DX 18-300mm F3.5-F6.3 zoom (which of course doesn't exist). That would result in an effective 27-450mm range in full-frame terms. Cropping the 24mp sensor to just 6mp would double the range to 900mm which would be sufficient, if the lens were of high quality, for most bird and wildlife shots, prints up to A3 size, and HDTV display.

Unfortunately, such lightweight, DX zoom lenses tend not to be sharp at the long end and generally show poor resolution at the edges and corners, so there is always a significant compromise in image quality for the convenience of that lighter weight and more useful FL range.

I can't help wondering if there is a technical obstacle to producing a lightweight zoom lens with such a range, which is really high quality. It would obviously have to be more expensive than the current Nikkor 18-300mm DX zooms, but I guess such a lens, if possible to design, would undermine the sales of existing heavier lenses.
Title: Re: comparining micro four thirds to full frame
Post by: BJL on March 08, 2018, 05:37:32 pm
BJL,
As I've mentioned before, whatever the ISO setting, one can overexpose or underexpose. At higher than base ISO, the internal amplification of the signal is fixed in accordance with the ISO setting and the camera design. The photographer doesn't have any control over that degree of amplification in relation to a specific ISO setting.
I agree that with a particular camera at a particular EI setting, that IF you can increase exposure to have the raw histogram at the right edge, it is better than giving less exposure. But that fact is of little use when judging or predicting IQ differences between different cameras that might apply a different amount of amplification at the same EI setting, or even comparing at different EI settings on the same camera. It is also a bit irrelevant in low light situations where one cannot vary the exposure because it is fixed (at well below full well capacity) by limits of minimum usable shutter speed and largest usable aperture. Then the question instead is something like deciding the best EI setting (analog amplification level) — and also deciding how much changes in EI setting matter: often very little in "near ISO-less" cameras.

However, we have dragged this thread far from its title, and I am not sure that anyone else cares! So maybe I will start another thread to discuss the use and abuse of "EXPOSE To The Right" and its evil twin "Raw Histogram After Amplification To The Right".
Title: Re: comparining micro four thirds to full frame
Post by: Ray on March 08, 2018, 10:57:31 pm
I agree that with a particular camera at a particular EI setting, that IF you can increase exposure to have the raw histogram at the right edge, it is better than giving less exposure. But that fact is of little use when judging or predicting IQ differences between different cameras that might apply a different amount of amplification at the same EI setting, or even comparing at different EI settings on the same camera. It is also a bit irrelevant in low light situations where one cannot vary the exposure because it is fixed (at well below full well capacity) by limits of minimum usable shutter speed and largest usable aperture. Then the question instead is something like deciding the best EI setting (analog amplification level) — and also deciding how much changes in EI setting matter: often very little in "near ISO-less" cameras.

BJL,
Sorry! Can't follow your logic. The purpose of the DXO measurements is to enable you to predict the IQ differences between different cameras that do in fact apply different amounts and different qualities of amplification at the same ISO setting.

How a camera behaves at a particular ISO setting is something that is useful to know in order to make the best choice of camera purchase, and also the best choices of ISO setting and F/stop, in relation to the desired shutter speed, when using the camera.

For example, it is well known that Canon DSLRs at base ISO have much worse DR than Nikon DSLRs. The Nikon D810 has a full 2 stops better DR than the Canon 5DSR at their nominated ISOs of 100, which are measured as being almost identical at ISO 77 for the 5DSR and ISO 75 for the D810.

However, as ISO settings are increased, that DR advantage of the D810 decreases. From ISO 800 onward, the DR is basically the same for both cameras, as well as the SNR. Isn't that useful to know?

Supposing, for example, that you are shooting a landscape where you consider that both DR and DoF is important, so you want to use your 5DSR at base ISO and and an f/stop of 16. Unfortunately, you haven't got your tripod with you and realize that at F16 and base ISO the shutter speed will be too slow for a sharp, hand-held shot, so an ISO setting of 200 might be more appropriate. This might result in a period of indecision if you don't know how your camera behaves at different ISOs. Is it better to sacrifice a bit of DoF and use F11, or better to sacrifice perhaps a full stop of DR for the sake of more DoF?

However, if you have examined DXO's test results for the Canon 5DSR, you will understand that the DR at ISO 200 is almost identical to the DR at the base ISO of 100. The difference is a mere 0.06 EV, of no consequence and probably within the margin of testing error.
If one is using the Nikon D810 in the same circumstances, increasing ISO to 200 will result in a drop of almost a full stop of DR, but that reduced DR is still more than a full stop better than the Canon 5DSR at ISO 200. Is that not useful to know?

Another example of the practical use of being aware of the different qualities of signal amplification in different cameras, relates to my first full-frame DSLR, the Canon 5D. It had impressively low noise at high ISOs, such as ISO 1600 and 3200 which I often used in low-light situations

However, it became widely known through various tests, before DXO began publishing its results, that using ISO 3200 with the Canon 5D served no purpose for those shooting in RAW mode. The camera merely amplified the signal without any further reduction in noise. An underexposure at ISO 1600 resulted in the same quality of image when the same exposure was used at ISO 3200, after appropriate adjustments in Photoshop's Camera Raw.

The advantage of underexposing at ISO 1600, instead of attempting an ETTR shot at ISO 3200, was better detail in the highlights, and/or lower risk of completely blowing some highlights. Is that sort of information not useful to know?
Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on March 09, 2018, 01:19:15 pm
It certainly has for Guillermo, but he used to be a fanatic about DR, even promoting a procedure known as UniWB to extract slightly more DR from an image by avoiding the clipping of perhaps just one color that could result from a camera-selected white balance.

I was never that fanatical.  ;D

I have never been a fanatical of anything but Alfa Romeo. If I made up a procedure for UniWB is just because at that time it was useful for my camera's poor DR and mostly because doing it was a beautiful engineering exercise. Using UniWB today is of very limited use for the reasons I gave here.

You should improve your deduction skills. Probably you consider David Coffin, a guy with 'DCRAW' on his car's plate a RAW fanatic.

(http://www.guillermoluijk.com/offtopic/dcoffin/plate.jpg)

Dave shoots JPEG.

Looking at your endless arguments on this thread makes me think you don't have a very reallistic vision of your own fanatism either

Regards
Title: Re: comparining micro four thirds to full frame
Post by: DP on March 09, 2018, 01:22:12 pm
btw what coffin is up to ? dcraw updates are long gone, no ?
Title: Re: comparining micro four thirds to full frame
Post by: Guillermo Luijk on March 09, 2018, 01:26:44 pm
He's not anymore interested in maintaining the code, but alive and living happily. DNG is very useful in this case.
Title: Re: comparining micro four thirds to full frame
Post by: Ray on March 09, 2018, 07:26:43 pm
You should improve your deduction skills.

How are your own deduction skills, Guillermo? Why do you appear to have ignored the 'smiley' in my comment about your fanaticism?  ;)

I understand quite well that DR becomes less of an issue as sensor DR improves generally. However, when comparing Micro Four Thirds to a Full Frame format which usually has a much higher pixel count, there are many other performance advantages of the full-frame format, which should be considered in total.

One major advantage which I've already addressed, is the greater range of 'equivalent' focal lengths with any given lens on full-frame, in relation to the minimum standard image quality and image size of the MFT format under comparison.

In other words, a 50mm prime lens on the full-frame format becomes an effective 50-100 mm zoom, equivalent to a 25-50 mm zoom on the MFT format, with possibly slightly worse image quality towards the 100mm end, depending on which camera models are compared, but almost certainly better image quality towards the short end when the larger full-frame image is downsized to the MFT size.
Title: Re: comparining micro four thirds to full frame
Post by: HSakols on March 13, 2018, 09:08:27 am
Nancy,

When it comes to hiking more than a couple of miles, I don't use a photo backpack.  Instead, I put my camera and lenses into smaller cases and put those in one of my Ospray backpacks.  This is much more comfortable.  Yes, my wife is only 5frt so I understand the difficulty of finding the right fit. 

Ray,

You have discussed dynamic range but what about comparing a high frequency images (eg a bush with lots of branches) to say an image of a mountain?
Title: Re: comparining micro four thirds to full frame
Post by: Ray on March 13, 2018, 10:31:18 am
Ray,

You have discussed dynamic range but what about comparing a high frequency images (eg a bush with lots of branches) to say an image of a mountain?

Hugh,
I'd be very interested to see such comparisons. At the wider end of any lens, prime or zoom, I'd expect the full-frame 35mm format to show a clearly sharper and less noisy image.

However, at the long end of the zoom effect, comparing the full frame of an MFT shot using a 50mm lens, with the cropped image of a D850 shot using a 50mm lens, (to make it an effective 100mm shot), the MFT shot would probably show greater  resolution, at least in the centre, depending on the quality of the lenses used and which cameras are being compared.

At the edges and corners, the cropped D850 image would probably be sharper than an E-M1 MkII shot at 50mm.

If I had the time and the motivation, I'd try to hire an E-M1 MkII with lenses, in order to do my own comparisons, to see how significant any differences are, not only between MFT and my Nikon FX cameras but also my DX cameras.
Title: Re: comparining micro four thirds to full frame
Post by: Frodo on March 17, 2018, 03:35:28 pm
Lots of theoretical analysis.
Or you could look here: https://www.dpreview.com/reviews/nikon-d850/8
The D850 beats the Olympus hands down.
As for the theoretical argument about equivalent DoF, get a cellphone. I find the shallow depth of field of FF one of the advantages for subject isolation, e.g. for weddings.
But I walked 450km through the Swiss Alps in 2016. I took my Canon M3 and two lenses and saved over a kilogram.
Horses for courses.
Title: Re: comparing micro four thirds to full frame
Post by: BJL on March 17, 2018, 03:56:47 pm
Lots of theoretical analysis.
Or you could look here: https://www.dpreview.com/reviews/nikon-d850/8
The D850 beats the Olympus hands down.
Of course it does — at least in situations where very high resolution or very shallow depth of field or handling scenes of very great subject brightness range without exposure bracketing are sufficiently important: the question here is how big the differences are in various situations, and if and when they are worth the extra cost/weight/bulk involved. As you conclude,
... But I walked 450km through the Swiss Alps in 2016. I took my Canon M3 and two lenses and saved over a kilogram.
Horses for courses.

As for the theoretical argument about equivalent DoF, get a cellphone. I find the shallow depth of field of FF one of the advantages for subject isolation, e.g. for weddings.
Let's not play this game of "people who are not as demanding as me about some aspect of performance will therefore be satisfied with the very low end of the performance spectrum". There is a huge difference between a cell phone's "f/16 equivalent DOF all the time, and the limited low light abilities that go with it" and what is available in 4/3" format — or APS-C, or even 1" format.
Title: Re: comparining micro four thirds to full frame
Post by: Frodo on March 21, 2018, 02:06:48 pm
Hi BJL
Totally agree with all your points.
We are on the same page.
Title: Re: comparining micro four thirds to full frame
Post by: HSakols on March 21, 2018, 06:56:15 pm
OK here are my rough comparisons between a Nikon D800 160mm f16 at iso 100 and an Olympus EM5 I 75mm f8 at iso 200.  I used a Nikon 70-200 f4 and the Olympus 75mm f1.8


Title: Re: comparining micro four thirds to full frame
Post by: Ray on March 22, 2018, 06:09:57 am
OK here are my rough comparisons between a Nikon D800 160mm f16 at iso 100 and an Olympus EM5 I 75mm f8 at iso 200.  I used a Nikon 70-200 f4 and the Olympus 75mm f1.8

Thanks for that, Hugh. The EM5 I image definitely looks better. It's just a pity the comparison is so rough. Perhaps we could say, for those who shoot rough, the EM5 I is a better camera.  ;D

For a start, it's not clear if these images are out-of-camera jpegs. They look like it. The D800 shot look underexposed.

When comparing the image quality from different cameras, especially when comparing resolution and noise in the shadows, it's essential to start off with RAW images that are fully exposed (ETTR), and ensure that the shots of the same scene have the same lighting, otherwise the comparisons are not valid.

Having download your images into ACR, I am very puzzled as to the exposures. According to DXOMark, the ISO sensitivities of both cameras are approximately equal. The EM5 I is a mere 1/4th of a stop less sensitive.

The metadata shows that the shutter speed for the Nikon shot at ISO 100 and F16 is 1.6 seconds. For the EM5 I at ISO 200 and F8, the shutter speed is 0.6 seconds.

If we equalize the ISO and the f/stop for both cameras, the shutter speed should be approximately the same, but it's not. There's a significant difference. What's going on?

At ISO 200 and F8, the shutter speed for the Nikon shot should be 1/8th of 1.6 seconds, which is 0.2 seconds, about 1.5 stops less exposure that the 0.6 second of the EM5.

Nevertheless, when an extensive DoF is required, the ability to use F8 instead of F16, or F11 instead of F22, with the MFT format, is a significant advantage, which I don't deny, all else being equal.
Title: Re: comparining micro four thirds to full frame
Post by: HSakols on March 22, 2018, 10:05:44 am
Ray,
I shot both of these using raw and didn't adjust the images.  But of course I converted to JPEG to post.  Yes the D800 image is underexposed.  Still I see better details in the D800 image - look at the glasses on the table.  Also there may be more noise in the the Olympus image.  But at a printed size of 16x20????   Yes, eventually I'm getting my hands on a D850, but I'll have to leave it home when I go on backpacking adventures because good lenses are just too heavy.   
Title: Re: comparining micro four thirds to full frame
Post by: Ray on March 22, 2018, 08:40:30 pm
Ray,
I shot both of these using raw and didn't adjust the images.  But of course I converted to JPEG to post.  Yes the D800 image is underexposed.  Still I see better details in the D800 image - look at the glasses on the table.  Also there may be more noise in the the Olympus image.  But at a printed size of 16x20????   Yes, eventually I'm getting my hands on a D850, but I'll have to leave it home when I go on backpacking adventures because good lenses are just too heavy.

Hugh,
If the 12mp of the Em5 Mk I is sufficient for your usual print size, then the advantages of the cropping options offered by the 45mp D850 should be taken into consideration when choosing lenses.

For example, the very light AF-S Nikkor 85mm F1.8G prime becomes effectively an 85-170mm/F1.8 zoom, with a maximum aperture of F1.8 across the entire zoom range, in relation to the 12mp of the OM5 I (approximately).

How much would such a zoom lens designed for the MFT format weigh and cost, with a maximum aperture of F1.8 at all focal lengths?  The Nikkor 85/F1.8 prime weighs only 350 grams and costs less than US$500.
Title: Re: comparining micro four thirds to full frame
Post by: Jack Hogan on March 23, 2018, 04:29:29 am
btw what coffin is up to ? dcraw updates are long gone, no ?

Libraw (https://www.libraw.org/download) seem to have picked up where he left off, they typically issue by-yearly updates.