comparining micro four thirds to full frame

[BJL]

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!

[Slobodan Blagojevic]

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).

[Ray]

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. 

[BJL]

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”.

[Ray]

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.

[Ray]

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. 

[LesPalenik]

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

[armand]

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.

[LesPalenik]

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?
   

[Ray]

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.  )

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. 

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

[Eric Myrvaagnes]

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

Only two of the pelicans seem to be trumpeting. The rest are asleep.

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

[Ray]

Only two of the pelicans seem to be trumpeting. The rest are asleep.

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

Oops! I should have written pair of pelicans. Glad you noticed the Canonbird. 

[BJL]

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.

[Ray]

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?

[Ray]

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.

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.

[LesPalenik]

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.

[Ray]

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.

[BJL]

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.

[Telecaster]

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-

[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.

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