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Author Topic: Has Canon fallen hopelessly behind? (cross-posted)  (Read 70137 times)

ErikKaffehr

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #40 on: March 29, 2012, 11:52:03 pm »

Ray,

The comparison I have made between 36MP and FF and 24MP APS-C was for resolution only.  Regarding DR, a frequent poster on these forums is "bclaff" who measures something he calls "Photographic DR". He has all his results posted. This link compares D800 and 5DIII: http://home.comcast.net/~NikonD70/Charts/PDR.htm#EOS%205D%20Mark%20II,D800,EOS%205D%20Mark%20III,D4

I have mentioned before that I don't see DR as the most important differentiator between cameras. An extended DR indicates good handling of readout noise and or large "full well capacity". To me it seems that Nikon can deliver on both readout noise and FWC with a 36MP sensor. In my view, there is no world of difference between 36MP and 24MP, but I certainly don't think that 36MP hurts.

Best regards
Erik

Absolutely! It's uncanny how close the pixel performance of the D7000 is compared with the D800, at DXOMark in screen mode. The differences are so small one could almost attribute them to QC differences in the manufacture of the cameras.

Where differences do seem significant, for example DR at ISO 12,800, which at first glance appears to be 0.81EV better in the D800, one finds this is mainly due to different ISO standards. The D800 at its nominated setting of ISO 12,800 is really ISO 8,661, whereas the D7000 is actually ISO 10,549, so the results indicate that the D800 pixel at its lower ISO of 8,661 has 0.81EV better DR than the D7000 pixel at its higher ISO of 10,549.

Visually, comparing points on the graph that are vertically aligned, the improvement appears to be of the order of 1/3rd of a stop, which is of no great consequence. However, these results are for the pixel. At equal print size, that DR advantage of the D800 at a real ISO of 10,549 is transformed to approximately one full stop, which I guess would be noticeable.

Where the Canon 5D2 lags greatly behind in these tests of DR is at low ISO. At ISO 1600 and above, it's not too bad compared with the D800, but at base ISO of 100 (actually 73 and 74), the D800 has a whopping 2 & 1/2 stops'  advantage, at equal print size.

As I understand, this would mean, when taking an ETTR shot of a high dynamic range scene, in order to get a similar level of detail and low noise in the deep shadows in the 5D2 shot, one would have to give 2 & 1/2 stops' greater exposure with the 5D2 than the D800 requires, thus massively blowing out the highlights.

It will be interesting to see how much improvement the 5D3 has in respect of DR at base ISO. I wonder why DXOMark are taking so long to test the 5D3.

http://www.dxomark.com/index.php/Cameras/Compare-Camera-Sensors/Compare-cameras-side-by-side/(appareil1)/792%7C0/(brand)/Nikon/(appareil2)/680%7C0/(brand2)/Nikon/(appareil3)/483%7C0/(brand3)/Canon


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KenS

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #41 on: March 30, 2012, 01:12:25 am »

... As I understand, this would mean, when taking an ETTR shot of a high dynamic range scene, in order to get a similar level of detail and low noise in the deep shadows in the 5D2 shot, one would have to give 2 & 1/2 stops' greater exposure with the 5D2 than the D800 requires, thus massively blowing out the highlights.

It will be interesting to see how much improvement the 5D3 has in respect of DR at base ISO. I wonder why DXOMark are taking so long to test the 5D3.

http://www.dxomark.com/index.php/Cameras/Compare-Camera-Sensors/Compare-cameras-side-by-side/(appareil1)/792%7C0/(brand)/Nikon/(appareil2)/680%7C0/(brand2)/Nikon/(appareil3)/483%7C0/(brand3)/Canon



Ray,
My understanding of the dynamic range improvement of the D800 at low ISO is the same as yours... and I think it IS a significant point, at least for what I shoot.  All my landscape images (which is all I shoot!) are done on a tripod, often stitched to increase resolution (I have several Canon TS-E lenses).  If the DR of the scene is too great I now need to combine two exposures with two (or more) shifted or rotated images.  I was hoping the 5Diii would have significantly increased DR at low ISO over the 5Dii but this does not appear to be the case.  If it did, it would be an important advantage, eliminating the need to composite both exposures and shifts (or focus blends and exposures).

Ken

Tony Jay

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #42 on: March 30, 2012, 01:17:23 am »

I am just starting to play with my 5D3 now and so far I feel that there is a practical improvement in DR but certainly not so much that it would consign HDR processing to history.

I am hoping that once I start doing HDR imaging with the camera (not the in-camera function) that better results are possible compared to the 5D2.
Time will tell.

Regards

Tony Jay
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nsnowlin

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #43 on: March 30, 2012, 03:12:10 pm »

I don't think so.  I read the D800 / D800E technical manual.  As an old 4x5 shooter it confirmed what we all know:  use a tripod, use live view, don't shoot over f8 unless diffraction isn't your concern (neither Canon or Nikon lenses best my old Schneiders here), check carefully for focus shift, etc.  There has been some discussion that the 22mp range is currently the engineering sweet spot for compromises in design for a general purpose pro camera to use in low light, high ISO, fast action, studio, reception lighting from hell, etc.  No doubt that will change and most likely by August in Canon's case.  The new Sony-Nikon chip is remarkable for DR at low ISOs (pardon me, ASAs).  You have to decide if the D800 is the best tool for what you primarily do.  For me it is not.  The 5D3 looks to me to be easier to live with for general photography.  This includes processing thousands of files a week, something that makes 36mp look daunting.  My 1Ds3 certainly was a great general purpose body but I really need the clean high ISO files to be competitive.  And the yet-to-be-released 1D X?  A flagship camera with USB-2?  If you have to shoot in the rain or sea spray and have Canon L glass this is your tool.

Stu
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JohnBrew

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #44 on: March 30, 2012, 03:23:29 pm »

Two items of note: the comparison's between the MkIII and D800 which I've seen so far indicate the MkIII is competitive with the Nikon and secondly for those who complain about the file size of 36mp you can always shoot at a lesser resolution.

BJL

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There has been some discussion that the 22mp range is currently the engineering sweet spot for compromises in design for a general purpose pro camera to use in low light, high ISO, fast action, studio, reception lighting from hell, etc.
In one respect, I am fairly sure that 16-18MP is currently that sweet spot, as indicated by the D4 and 1Dx. That respect is simply the maximum that is compatable with the highest frames that the makers can get from the other components of those models. As to the 22MP of the 5D3, that is a slightly diferent sweet spot: its horizontal pixel count (as I predicted before the exact figure was published) is 5760 = 3 x 1920, fitting perfectly with the sub-sampling or down-sampling needed to produce 1920x1080 HD video.
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Erick Boileau

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #46 on: March 31, 2012, 12:01:42 am »

I  (and we are many) don't want 36mp on a 24x36 , 18 mp ... 22mp are enough  on  a small sensor
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tom b

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #47 on: March 31, 2012, 12:24:48 am »

Where can we see this high dynamic range?

Cheers,
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Tom Brown

ErikKaffehr

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #48 on: March 31, 2012, 02:12:32 am »

Hi,

Typical area would be high contrast scenes like a picture taken in a dark church where we need to capture a mosaic window and still keep good detail in the shadows. Architecture photographers may need it for interiors and so.

In landscape photography we may need high DR in situations like this:



The image here was produced from a single exposure with a Sony Alpha 100 camera, vintage 2006 that had a very limited DR. The full image is here: http://echophoto.dnsalias.net/ekr/images/PublishedPictures/SonyAlpha100_DR_example.jpg

My experience this far has been that all DSLRs I have been using had ample DR for my needs. There is always an option to use HDR (combining several exposures into one) but I have seldom needed it.

So, in my view DR is an important quality in a camera, but it may be somewhat overrated. Here is a short discussion on extracting info from a single image: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/63-lot-of-info-in-a-digital-image

Now, it is quite obvious that Nikon (and Sony whose sensor technology Nikon uses) made significant strides in extending DR, obviously they have reduced readout noise by integrating a massive number (thousands!) of ADCs on the sensor itself. Having the ADC on chip eliminates most of the signal path, and having a large number allows for long conversion time. For instance if we have 36MP and 7000 redout channels at 4FPS we would have 20 000 samples/s per ADC. With 21 MP and 8FP using four ADCs we would have 42 000 000samples/s. I don't know how many readout channels the EOS 5DIII has, it is just an illustration.

The other area there Nikon/Sony seems to may have progress is increasing the Full Well Capacity (FWC) of the pixels. FWC is essentially the parameter that determines shot noise in an image that is correctly "exposed to the right", with non specular highlights just before clipping. So it seems that Nikon/Sony expanded DR at both ends.

I enclose a comparison of Nikon D800, Canon 5DII and the Sony Alpha 100 that was used  for the image by DxO-mark. The data for the 5DIII are unfortunately not available yet.

Best regards
Erik

Where can we see this high dynamic range?

Cheers,
« Last Edit: March 31, 2012, 03:49:55 am by ErikKaffehr »
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Erik Kaffehr
 

BJL

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Why is more than 22MP useful, but not in 36x24mm format?
« Reply #49 on: March 31, 2012, 08:35:36 am »

I  (and we are many) don't want 36mp on a 24x36 , 18 mp ... 22mp are enough  on  a small sensor
You seem to imply that there is a use for more than 22MP, but only in formats larger than 36x24mm. Why?
The only reasons I can see are that lens resolution is not adequate or that per pixel performance in noise levels, dynamic range or such are inadequate. Factors like that probably will one day set upper limits on useful resolution that are higher for larger formats than in smaller formats, but we are not there yet:
- a number of Nikon lenses can give a clear increase in resolution with 36MP than they give with 24MP or less, and in fact have already been doig so for years with the highest resolution black and white film like TMAX 100, whcih easily resolves well beyond what a 22MP sensor can give.
- per pixel levels of dark noise, dynamic range and such for the D800 sensor are clearly better than in any current MF sensors, due to MF being stuck with the obsolescent, noisy CCD type of sensor while Nikon and Sony are advancing the state of the art.

Another point is that a large proportion of photographic situations do not need extremes of high DR and low dark noise, becuase the scene will be printed normally without manipulation of contrast and levels, and then any noise more than about nine stops below brightest highlights and six stops below midtones will be imperceptible. Prints have less than seven stops between pure white and pure black, and less than five stops from mid-tones fo pure black (Ansel Adams had some comments on these limits!) Clearly 36x24mm format can go further in resolution before hitting that level. For other images involving scenes og high subject brightness range, like Erik K.'s examples above (a distinct minority of images overall, I suspect), the option of more DR, less shadow noise and lower resolution is there with downsampling or NR processing, so there is no need to hobble the camera's resolution in other situations for the sake of those hard cases.
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Petrus

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Re: Why is more than 22MP useful, but not in 36x24mm format?
« Reply #50 on: March 31, 2012, 02:02:15 pm »

the highest resolution black and white film like TMAX 100, whcih easily resolves well beyond what a 22MP sensor can give.

I would like to see some samples on this. Reason: already the ancient 16 MPix EOS-1Ds was equal or better than 645 Provia. Now APS-C sized sensors (Fuji X-Pro1 etc) are clearly better than 645 slide, best FF sensors (D800) equal 6x9 and MF sensors are better than 8x10".

So I am curious.

(and how about Technical Pan?)
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kers

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #51 on: March 31, 2012, 03:01:40 pm »


Why is that? Resolution? Really? Resolution is 99% hype. It does nothing at all for image quality. A good photo at 12mp is better than a mediocre photo at 36mp. And is THAT fact that most people either do not understand or do not want to.

Why is that? Resolution? Really? Resolution is 99% hype. It does nothing at all for image quality. A good photo at 36mp is better than a mediocre photo at 36mp. And is THAT fact that most people either do not understand or do not want to.
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BJL

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Re: Why is more than 22MP useful, but not in 36x24mm format?
« Reply #52 on: March 31, 2012, 03:21:01 pm »

I would like to see some samples on this. Reason: already the ancient 16 MPix EOS-1Ds was equal or better than 645 Provia.
(and how about Technical Pan?)
Sorry, I do not have samples, and am using the extreme case of slow, fine-grained B&W film just to show that some photographers have already pushed the resolution limits of their 35mm format lenses further than  22MP or even 35MP sensor does, even if most have not. Also, resolution alone is not a good measure of overall "enlargeability", since film grain can make an image look coarser than low noise digital even when the film is resolving finer details.

I am looking at MTF, where TMAX 100 has a very high 70% MTF at 100 lp/mm, about at the the Nyquist limit of any resolution for the D800, even before allowing for the resolution loss to demosaicing, and so surely well beyond what any 22MP Bayer CFA sensor can do, for example. At the more common standard of 50% MTF, TMAX 100 resolves to 125 lp/mm, needing at least 9000x6000 = 54MP to match in 35mm format.

But I agree that color film was surpassed for resolution (with sensible measures like 50% MTF, not extinction resolution with extremely high resolution targets) a long time ago, by about 14MP at most for 35mm format.

I used TMAX 100 as my example because it has even higher resolution than the discontinued Technical Pan. The latter has 100lp/mm resolution at 50% MTF with the right developer, compared to 125lp/mm for TMAX 100. Still enough for Tech Pan to outresolve a 22MP sensor in 35mm format, and about match oroutresolve the D800.


P. S. there is anyway far simpler evidence that many Nikon and Canon lenses have the resolution to make use of pixels smaller than those of a 22MP sensor in 35mm format, at least in the central part if the image. Because that pixel size gives only about 10MP in Nikon's DX format, a bit less in Canon's E-FS, and in both systems, numerous lenses have been seen to be good enough to give a substantial increase in image resolution beyond that 10MP level when used with 16MP DX sensors or 18MP E-FS sensors ... and even up to 24MP with Sony lenses on its APS-C format bodies. I used the example of film instead becuase that has already tested lenses all the way to the edges of the full 36x24 frame.

Does anyone remember the days when many forum posters declared that APS-C format could not make use of more than about 6MP, and 4/3 no more than its original 5MP? Some people are too quick to onclude that "they've gone about as far as they can go", at least when talking of a format smaller that some favored size.
« Last Edit: March 31, 2012, 03:43:02 pm by BJL »
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Erick Boileau

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Re: Why is more than 22MP useful, but not in 36x24mm format?
« Reply #53 on: April 01, 2012, 02:23:42 am »

You seem to imply that there is a use for more than 22MP, but only in formats larger than 36x24mm. Why?
in my opinion big pixels are better,  it will be good to compare  RAWs at f/16
and who needs more than 22mp  ? 0.1% of photographers ?
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ErikKaffehr

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Re: Why is more than 22MP useful, but not in 36x24mm format?
« Reply #54 on: April 01, 2012, 03:12:05 am »

Hi,

Why exactly are big pixels better in your view?

If we take the Canon 7D, it has 18 MP with 1.6 crop factor, it would correspond to 46 MP on full frame. I got the impression that the 7D is pretty good.

Best regards
Erik

in my opinion big pixels are better,  it will be good to compare  RAWs at f/16
and who needs more than 22mp  ? 0.1% of photographers ?
« Last Edit: April 01, 2012, 03:17:34 am by ErikKaffehr »
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Erik Kaffehr
 

Petrus

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Re: Why is more than 22MP useful, but not in 36x24mm format?
« Reply #55 on: April 01, 2012, 03:21:32 am »

in my opinion big pixels are better,  it will be good to compare  RAWs at f/16
and who needs more than 22mp  ? 0.1% of photographers ?

Cramming more tiny pixels into a 35mm sized sensor makes the diffraction problem bigger. 22 MPix FF sensor already starts to loose resolution at f:8. MF sized sensor has f:8 as the diffraction limit at 60 MPix. Besides bigger pixels have less noise, better high ISO. For landscape photography sharp, small sensors are a problem as stopping down brings the effective resolution to around 5 MPix only (f:16-22 with FF sensor). With larger sensor with same MPix you can stop down more, which compensates most of the lost DOF when moving to bigger size sensor (but not all).

Comparing RAWs at f:16 means comparing two 7 MPix images, no matter what the original pixel count is on those two FF cameras.
« Last Edit: April 01, 2012, 03:23:55 am by Petrus »
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ErikKaffehr

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Re: Why is more than 22MP useful, but not in 36x24mm format?
« Reply #56 on: April 01, 2012, 04:03:46 am »

Hi,

A few objections.

1) Shot noise is not dependent on pixel size just sensor size. If you collect 60000 photons it doesn't matter if you collect them in one single bin or four bins, they are still 60000 photons. DR is a bit different and there is some advantage to larger pixels.

2) No real evidence that bigger pixels are better at high ISO. Think of old MF backs with big pixels, they never had good high ISO.

3) Diffraction is rather benign to sharpening, as diffraction essentially has a cone shape, it reduces edge contrast but diminishes resolution less.

It is quite obvious that stopping down reduces resolution and it's little idea to decrease pixel pitch much beyond diffraction limit, but most pictures are probably not taken at f/16 but possibly around f/8 (like "F/8 and be there").

The enclosed DxO mark measurement of noise illustrates pretty well that both noise and high ISO behavior on D800 and D4 is quite similar. The D800 much better DR at base ISO than he D4, depending on better sensor technology. The D4 has an advantage in DR at high ISO. That correlates with my first statement.

Best regards
Erik





Cramming more tiny pixels into a 35mm sized sensor makes the diffraction problem bigger. 22 MPix FF sensor already starts to loose resolution at f:8. MF sized sensor has f:8 as the diffraction limit at 60 MPix. Besides bigger pixels have less noise, better high ISO. For landscape photography sharp, small sensors are a problem as stopping down brings the effective resolution to around 5 MPix only (f:16-22 with FF sensor). With larger sensor with same MPix you can stop down more, which compensates most of the lost DOF when moving to bigger size sensor (but not all).

Comparing RAWs at f:16 means comparing two 7 MPix images, no matter what the original pixel count is on those two FF cameras.
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Ray

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Re: Has Canon fallen hopelessly behind? (cross-posted)
« Reply #57 on: April 01, 2012, 05:25:18 am »

Hi,

Typical area would be high contrast scenes like a picture taken in a dark church where we need to capture a mosaic window and still keep good detail in the shadows. Architecture photographers may need it for interiors and so.

In landscape photography we may need high DR in situations like this:

My experience this far has been that all DSLRs I have been using had ample DR for my needs. There is always an option to use HDR (combining several exposures into one) but I have seldom needed it.

So, in my view DR is an important quality in a camera, but it may be somewhat overrated. Here is a short discussion on extracting info from a single image: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/63-lot-of-info-in-a-digital-image



Erik,
One always has to work within the limitations of one's tools. DR, tonal range, SNR, resolution etc are to me all desirable qualities in any image, but not all images (or prints) require those qualities to the same degree.

The classic example is Michael's comparison of A3+ size prints of a woodland scene from a Canon G10 P&S and a Phase P45. No-one was able to identify which camera was the origin of which print.

From memory, the nature of the subject was not ideal for comparing DR because the patches of sky visible through the foliage were blown in the both shots, but presumably to different degrees. The rough texture of a forest was not an ideal subject for comparison of SNR at 18% grey, so that particular feature in which the P45 excels would have passed unnoticed. The 10mp of the Canon G10 is ample resolution for an A3+ size print, so the obvious advantages of the higher resolution of the P45 would also have passed unnoticed.

Eventually, someone noticed a shallower DoF in one of the prints, so that was the clue. I can't help wondering what the result might have been if Michael had been more rigorous in the comparison and reshot the scene at F22 with the P45, instead of the F11 that was used. Would the resolution of the P45 at F22 have been noticeably less at A3+ print size? Would the slower shutter speed have resulted in a noticeable blurring due to leaf movement, in the P45 shot?

You, Erik, claim that you don't really need more DR than current cameras provide, then present an image to support your view, of a high DR scene (or scene with high SBR, as BJL prefers) which has terribly noisy shadows.

I know black can be beautiful, but I've often wondered if the custom of blackening shadows on prints has arisen mainly, or at least partly, because of the dynamic range limitations of film or sensor. Sometimes a blackened silhouette can be very striking, but sometimes there might be interesting detail in them thar shadows which the eye actually does perceive in the actual scene before the shutter was pressed.

I've been searching my recent images for one that demonstrates my point; that is, an image with a high SBR which also has detail in deep shadows which one may wish to preserve.

I think the following shot of a beach scene in Thailand, about a couple of hours before sunset, fits the bill. As I was walking back to the hotel, part of the route went alongside the beach and I noticed a dramatic change in the weather. I find clouds interesting. I was carrying my D7000 with 14-24/2.8 attached. The following shot was taken at 24mm, or 36mm FF equivalent.

The shot is close to being an ETTR, although I think I might have got away with using an 80th instead of the 100th. However, I prefer to err on the side of underexposure, especially when  using a camera such as the D7000 with a high DR.

Now this is an image which clearly has to be processed. If I'd been in jpeg mode, then forget it. But what sort of processing is right, or best, or preferred?  It was mainly the dark clouds in contrast with the bright sunlight squeezing in below, which caught my attention. I waited for someone to walk along the beach to add foreground interest. I don't think it would be natural for those figures to be blackened silouhettes. This scene was well before sunset, and the detail in the figures was clearly visible to my eye when I took the shot.

Likewise, the few leaves that partially frame the shot, were visible in detail when I took the shot. I like leaves, and these leaves are interesting and unusual. They are unusually large, which is no doubt partly why many Thais cover their roofs with them.

So this is the problem. At one end of the scale I've got almost direct sunlight, and at the other end of the scale I've got perfectly clear and visible detail which is rendered unnaturally dark by the camera.

If the camera has a poor dynamic range, I'm obviously going to keep those shadows unnaturally dark. That's preferrable to noise and grunge.

However, with a D7000, and particularly with a D800, I may be able to make those shadows presentable, as I think they are in the images below which include 100% crops.

Cheers!  Ray
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BernardLanguillier

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Re: Why is more than 22MP useful, but not in 36x24mm format?
« Reply #58 on: April 01, 2012, 06:42:25 am »

Hi,

A few objections.

1) Shot noise is not dependent on pixel size just sensor size. If you collect 60000 photons it doesn't matter if you collect them in one single bin or four bins, they are still 60000 photons. DR is a bit different and there is some advantage to larger pixels.

How about the role of the lens in concentrating light?

I would think that the size of the sensor is in fact irrelevant. What matters is the true T stop of the lens, is it not?

Cheers,
Bernard

BJL

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Diffraction effects at equal DOF are equal for all formats: f-stop varies
« Reply #59 on: April 01, 2012, 09:32:03 am »

Cramming more tiny pixels into a 35mm sized sensor makes the diffraction problem bigger.
How many times does this myth have to be debunked?!

The truth is that once you need to use a small aperture (high aperture ratio) in order to get enough depth of field, the effect of difraction is the same in any format, so the degree of the problem of balancing DOF againsts diffraction is almost entirely dependent on the image resolution that you are aiming for, or loosely speaking, on the pixel count.

Your mistake is comparing at equal f-stop, forgetting that with a larger sensor amd thus a larger focal length needed to get the same composition, the DOF is less in the larger format in proportion to focal length/format size. So tomget equal DOF, the large format needs to increase f-stop inroportion to focal length, which increases diffraction effects so that on same sized prints, both diffraction effects and OOF effects are equal.

Smaller formats have a disadvantage if one is seeking so much resolution that the f-stop needed to control diffrcation in a smaller format is so low rhat lens abberations become a significant factor. With 36MP in 35mm format, f/8 is fine for avoiding any problems, so we are not there yet. If you wish to avoid going below f/5.6, the resolution limit would be reached by about 120MP. Even in tiny 4/3" format, where many lenses have resolution sweet spot at f/4 or lower, the limits due to diffraction would. Ot be hit until about 60MP. In each case, I expect that other factors will limit resolution before diffraction does.
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