Dynamic Range & Camera IQ

[dtaylor]

tonal range is going to be similar for most cameras because they have a similar overall signal to noise ratios around midtones, despite the differences in overall DR
...
This is where medium format digital has an advantage with their big clean pixels and 16 bit digitizing, they seem to be able to produce better tonal gradients in the midtone and lower levels which make for smoother looking images than you get from smaller sensors.  You can see this same effect to some extent by comparing FF 35mm digital with compact cameras.
...
however, most of that's rendered moot when final output is 8 bit-per color jpeg or similar 8 bit files used for printing.

Truth. There are tonal and color differences with big jumps (compact >> DSLR >> MF), but not so much with small jumps. And those differences don't necessarily make it to screen or print.

[jrista]

There is something so seriously wrong with that 5D II image. There is red banding and FPN throughout the entire image, even the highlights. There is NO WAY that image was properly exposed in the first place. I've seen that kind of banding in sample black-frame 5D II images, but only after pushing exposure by about 8 stops, or by opening the image in PS/ACR and using the levels tool to drop the white point to within a fraction of the black point. The 5D II's maximum saturation is 64600e- and its read noise at ISO 100 is 28e-. That is a ratio of 2307:1! No friggin way your going to see that kind of banding with a minor curve bump like you've demonstrated. That exposure would have to be underexposed by many stops to exhibit like that. I cry fowl!!

BTW, banding noise IS READ NOISE. Read noise is a bit too specific, as that generally refers to the noise introduced by the ADC. I tend to refer to electronic noise, which comes in a variety of forms, but is all very low relative to maximum signal (even when there is 28 electrons worth!) Its a bunch of bullhonkey when you mentioned before that banding is not taken into account when determining DR...absolutely it is, its simply that DR is computed as the AVERAGE of read noise to maximum saturation. Since it is the average of electronic noise, that that would mean your computing DR as the ratio between what would roughly be 14e- and 64600e-, a ratio of 4614:1 (or 11.something stops), so some electronic noise...such as banding...will show through in very deep shadows.

Sorry nothing wrong with this comparison, this is a example how you can handle  the cameras , equal in terms of exposure and then adjust the images  identical  in Photoshop.

AND there is nothing as a proper exposure, some of you are living in a MYTH.
Banding and pattern noise from Canon are produced for instant that the 8, 16  readout locations not are in line with each other

[/quote]

The 5D II images appear to be very under exposed to me (and apparently, not just me). A "proper" exposure is one in which the image is NOT under exposed. And since the tests are comparing the recoverability aspects of both cameras, then you should be over exposing the 5D II image a bit, as Canon sensors have considerable highlight headroom. I bet you could over-expose the 5D II image by 2 stops, fully recover all the highlights, and have shadows that look nearly as good as the D800's.

[ecka]

Image quality, dynamic range, high ISO noise, graphs, numbers, SNR (signal to noise ratio) ... all that makes a lot of sense when you know what it is all about. For me it's all about camera's per-pixel color reproduction performance.

I care about images, not pixels. People that obsess with per-pixel image quality seems to be less interested in images that I am.

Per-pixel quality is academically interesting, but if you ever print your images or show them on a display, then that is the final indicator of quality. A 3 megapixel camera might have fantastic per-pixel quality (far better than my 7D), but who cares as long as my 7D takes better images??

-h

It's like saying "I care about milk, not cows" . I'm talking about pixel color accuracy and fake resolution. Have a look at some Sigma DP2 Merrill RAW samples (ISO 100) and you'll see what's the difference between the real 15 megapixel resolution and the fake 18 or 22 megapixel resolution from 7D or 5D3. Properly interpolated Merrill's RAW can give you a nice 30-40 megapixel Bayer-like image.
Please don't reply if you don't care.

[jrista]

There is something so seriously wrong with that 5D II image. There is red banding and FPN throughout the entire image, even the highlights. There is NO WAY that image was properly exposed in the first place. I've seen that kind of banding in sample black-frame 5D II images, but only after pushing exposure by about 8 stops, or by opening the image in PS/ACR and using the levels tool to drop the white point to within a fraction of the black point. The 5D II's maximum saturation is 64600e- and its read noise at ISO 100 is 28e-. That is a ratio of 2307:1! No friggin way your going to see that kind of banding with a minor curve bump like you've demonstrated. That exposure would have to be underexposed by many stops to exhibit like that. I cry fowl!!

BTW, banding noise IS READ NOISE. Read noise is a bit too specific, as that generally refers to the noise introduced by the ADC. I tend to refer to electronic noise, which comes in a variety of forms, but is all very low relative to maximum signal (even when there is 28 electrons worth!) Its a bunch of bullhonkey when you mentioned before that banding is not taken into account when determining DR...absolutely it is, its simply that DR is computed as the AVERAGE of read noise to maximum saturation. Since it is the average of electronic noise, that that would mean your computing DR as the ratio between what would roughly be 14e- and 64600e-, a ratio of 4614:1 (or 11.something stops), so some electronic noise...such as banding...will show through in very deep shadows.

Sorry nothing wrong with this comparison, this is a example how you can handle  the cameras , equal in terms of exposure and then adjust the images  identical  in Photoshop.

AND there is nothing as a proper exposure, some of you are living in a MYTH.
Banding and pattern noise from Canon are produced for instant that the 8, 16  readout locations not are in line with each other

The 5D II images appear to be very under exposed to me (and apparently, not just me). A "proper" exposure is one in which the image is NOT under exposed. And since the tests are comparing the recoverability aspects of both cameras, then you should be over exposing the 5D II image a bit, as Canon sensors have considerable highlight headroom. I bet you could over-expose the 5D II image by 2 stops, fully recover all the highlights, and have shadows that look nearly as good as the D800's.

sorry but you are wrong,  there is nothing like a proper exposure , you can expose as much as possible without clipping
and even then you can see the differences in the scene depending on how high/large  dynamic range the  scene has.
There is always a difference between 11 stops or 14 and 14 without pattern noise or banding
SO GO down in levels.


[/quote]

Well, I'm tired of swapping anecdotes with you. When you are ready to talk facts with proper reference and theory, I'll be waiting.

[dtaylor]

sorry but you are wrong,  there is nothing like a proper exposure ,

 

There is most certainly a proper exposure if you wish to maximize image quality given the medium you are working with. This is true for B&W, slide, color neg, and each specific model of digital sensor. If Canon's strength is on the highlight side and Nikon's on the shadow side then you must tailor exposure to each one.

[ecka]

Image quality, dynamic range, high ISO noise, graphs, numbers, SNR (signal to noise ratio) ... all that makes a lot of sense when you know what it is all about. For me it's all about camera's per-pixel color reproduction performance.

I care about images, not pixels....

It's like saying "I care about milk, not cows" .

Yes, that is a very good analogy.

If you are a milk-drinker, the quality of the milk will probably affect the drinking experience. The color of the cow _might_ affect the drinking experience.

So why are you saying that you care more about the cow than the milk (to follow the analogy)?

-h

I suggest you start reading more carefully. I never said that I care more about the cow than the milk. I care about both actually. The thing is - if "cows" are fine then the "milk" is fine automatically, but not 'vice versa'.

[dtaylor]

It's like saying "I care about milk, not cows" . I'm talking about pixel color accuracy and fake resolution. Have a look at some Sigma DP2 Merrill RAW samples (ISO 100) and you'll see what's the difference between the real 15 megapixel resolution and the fake 18 or 22 megapixel resolution from 7D or 5D3.

Foveon is another area of great hyperbole in photography. An 18 MP Bayer sensor does not have "fake" resolution. There are 18 million sample points of luminance data. And a Foveon sensor does not have 3x its pixels in resolution. 15 MP Foveon has 15 million sample points of luminance data.

Foveon sensors do have more sample points of color data, and this results in better images then a mere count of MP would suggest. That can be seen and should not be denied. But it's not the night and day difference claimed by fans. Nor will they scale to match 30-40 MP Bayer images. This is the hyperbole. Go ahead and photograph a landscape with foliage using the Sigma and a D800e and see how the Sigma fares scaled to match.

With that out of the way, I wish Foveon would have had a chance with a larger and more aggressive company like Nikon or Canon. The technology is interesting. If it could have been pushed up in MP and ISO at a faster pace it might have had a much greater impact on the market. Again, it's not night and day. But it's certainly a strong edge in IQ.

[jrista]

It's like saying "I care about milk, not cows" . I'm talking about pixel color accuracy and fake resolution. Have a look at some Sigma DP2 Merrill RAW samples (ISO 100) and you'll see what's the difference between the real 15 megapixel resolution and the fake 18 or 22 megapixel resolution from 7D or 5D3.

Foveon is another area of great hyperbole in photography. An 18 MP Bayer sensor does not have "fake" resolution. There are 18 million sample points of luminance data. And a Foveon sensor does not have 3x its pixels in resolution. 15 MP Foveon has 15 million sample points of luminance data.

Foveon sensors do have more sample points of color data, and this results in better images then a mere count of MP would suggest. That can be seen and should not be denied. But it's not the night and day difference claimed by fans. Nor will they scale to match 30-40 MP Bayer images. This is the hyperbole. Go ahead and photograph a landscape with foliage using the Sigma and a D800e and see how the Sigma fares scaled to match.

Well said! 

With that out of the way, I wish Foveon would have had a chance with a larger and more aggressive company like Nikon or Canon. The technology is interesting. If it could have been pushed up in MP and ISO at a faster pace it might have had a much greater impact on the market. Again, it's not night and day. But it's certainly a strong edge in IQ.

Ditto. I was pretty excited when I saw the patent from Canon for a layered sensor design. I've looked at it a few times, and I'm not sure it compared to the current Foveon patens from Sigma, but I really hope/wish they would develop the technology further. I could totally go for a 22mp layered sensor.

[ecka]

It's like saying "I care about milk, not cows" . I'm talking about pixel color accuracy and fake resolution. Have a look at some Sigma DP2 Merrill RAW samples (ISO 100) and you'll see what's the difference between the real 15 megapixel resolution and the fake 18 or 22 megapixel resolution from 7D or 5D3.

Foveon is another area of great hyperbole in photography. An 18 MP Bayer sensor does not have "fake" resolution. There are 18 million sample points of luminance data. And a Foveon sensor does not have 3x its pixels in resolution. 15 MP Foveon has 15 million sample points of luminance data.

Foveon sensors do have more sample points of color data, and this results in better images then a mere count of MP would suggest. That can be seen and should not be denied. But it's not the night and day difference claimed by fans. Nor will they scale to match 30-40 MP Bayer images. This is the hyperbole. Go ahead and photograph a landscape with foliage using the Sigma and a D800e and see how the Sigma fares scaled to match.

With that out of the way, I wish Foveon would have had a chance with a larger and more aggressive company like Nikon or Canon. The technology is interesting. If it could have been pushed up in MP and ISO at a faster pace it might have had a much greater impact on the market. Again, it's not night and day. But it's certainly a strong edge in IQ.

I mentioned the Foveon X3 as a benchmark for Bayer sensor in terms of resolution (per-pixel color accuracy at low ISO). I'm not saying that Foveon X3 has 3x it's pixels in resolution. It's more like Foveon X3 delivers 95% of it's sensor resolution, while Bayer delivers only 30-80% of it's sensor resolution (depending on pixel size). Sigma cannot compete at ISO 400+, it's too noisy, but at ISO 100 there is a nigh and day difference compared to 18MP APS-C and even 22MP FF seems to be not quite as good. Google it . It does scale nicely up to 30-40MP, even if it is foliage landscape. However, D800E may have the edge, but it's not like night and day difference .

[jrista]

It's like saying "I care about milk, not cows" . I'm talking about pixel color accuracy and fake resolution. Have a look at some Sigma DP2 Merrill RAW samples (ISO 100) and you'll see what's the difference between the real 15 megapixel resolution and the fake 18 or 22 megapixel resolution from 7D or 5D3.

Foveon is another area of great hyperbole in photography. An 18 MP Bayer sensor does not have "fake" resolution. There are 18 million sample points of luminance data. And a Foveon sensor does not have 3x its pixels in resolution. 15 MP Foveon has 15 million sample points of luminance data.

Foveon sensors do have more sample points of color data, and this results in better images then a mere count of MP would suggest. That can be seen and should not be denied. But it's not the night and day difference claimed by fans. Nor will they scale to match 30-40 MP Bayer images. This is the hyperbole. Go ahead and photograph a landscape with foliage using the Sigma and a D800e and see how the Sigma fares scaled to match.

With that out of the way, I wish Foveon would have had a chance with a larger and more aggressive company like Nikon or Canon. The technology is interesting. If it could have been pushed up in MP and ISO at a faster pace it might have had a much greater impact on the market. Again, it's not night and day. But it's certainly a strong edge in IQ.

I mentioned the Foveon X3 as a benchmark for Bayer sensor in terms of resolution (per-pixel color accuracy at low ISO).

I think your falling into the same trap as most when comparing a Foveon with a Bayer. Bayer is only limited relative to Foveon in terms of color fidelity. A layered sensor design is capable of much greater color fidelity and accuracy because its capturing a full quantity of color information at every photosite. That also gives it another slight edge as it does not need a low-pass filter to eliminate color moire, since color moire doesn't exhibit. However Bayer sensors ARE detecting luminance data at every photosite, and there is no question they are capable of discerning a finer gradation of detail than a Foveon sensor...DESPITE the fact that their pixels are interpolated. I'm not sure an 18mp FF sensor is really going to be a significant edge, resolution wise, over a Foveon. But an 18mp APS-C sensor is going to resolve considerably more detail than a 15mp Foveon, and for that matter more detail than a 36.3mp sensor. Similarly, a 46.1mp FF sensor is going to be capable of the same resolving power as an 18mp APS-C.

The three-fold difference in luminance resolution and a far greater number of color pixels, several stops better ISO performance, and much greater spatial resolution, even when factoring in interpolation, gives a significant edge to Bayer in this case.

[Aglet]

..the patent from Canon for a layered sensor design. I've looked at it a few times, and I'm not sure it compared to the current Foveon patens from Sigma, but I really hope/wish they would develop the technology further. I could totally go for a 22mp layered sensor.

they could, maybe
but isn't that layered sensor exactly what they're now using as the color-sensitive AE sensor that's been used in most bodies since the 7D came out with it...
I like it, metering and AWB has been much better since it's arrived

[dtaylor]

Ditto. I was pretty excited when I saw the patent from Canon for a layered sensor design. I've looked at it a few times, and I'm not sure it compared to the current Foveon patens from Sigma, but I really hope/wish they would develop the technology further. I could totally go for a 22mp layered sensor.

Maybe the 3D is a 46 MP layered sensor. Shut all the Nikon guys up 

Only problem is that if that were true it would cost $10k 

[Aglet]

Ditto. I was pretty excited when I saw the patent from Canon for a layered sensor design. I've looked at it a few times, and I'm not sure it compared to the current Foveon patens from Sigma, but I really hope/wish they would develop the technology further. I could totally go for a 22mp layered sensor.

Maybe the 3D is a 46 MP layered sensor. Shut all the Nikon guys up 

Only problem is that if that were true it would cost $10k 

I asked a Canon rep if they intended to do anything like that back when Foveon first hit the scene.
The negative response was, of course, meaningless.
Like politicians, mfrs will deny deny deny until it suits them to do otherwise.
So, here's hoping Canon has some geniune ingenuity to show us for next year.

Somehow I can just imaging their engineering staff pacing feverishly, saying, "Dammit!  How could you announce something like that?!? We don't even have a working prototype!"

[PVS]

I can discuss facts whenever you want
I do not think I am the one who has trouble to understands facts= DR full well capacity, QE and read out noise+ banding and pattern noise

First of all - all that bolding is childish and unnecessary, it doesn't really help you make your point come through, it just makes you  seem rude.

Secondly, stop confusing DR with exposure latitude, DR isn't actually about how much you can under/over expose, especially not about doing it in post-process. Seriously.

[rpt]

Somehow I can just imaging their engineering staff pacing feverishly, saying, "Dammit!  How could you announce something like that?!? We don't even have a working prototype!"

I know the feeling. When you are hit with that kind of situation as the person responsible for delivery, you are angry and wonder "what were they thinking?". But then in hindsight, it is better to be challenged rather than be left alone in one's comfort zone. This is the story about a multitasking communication software my group developed that worked on DOS 3.x! And for those who wonder why it is a big deal, well one is only allowed to use the words "multitasking" and "DOS" in a sentence when the word "NOT" is placed in between them...