# 16 bit color anyone?



## RedEye (Feb 23, 2012)

If the technology has improved and the sensor pix count the same, is there any chance that it goes 16 bit color similar to many medium formats? Is a neat idea and the colors and contract could be stunning .


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## CrimsonBlue (Feb 23, 2012)

Jumping to 14-bit was a nice improvement, but for super-fast cameras, the amount of extra data passing through would reduce FPS without some other compensatory technology. 

Medium format doesn't usually have more than a frame or two per second so it can process more data and not have to worry about filling/emptying a buffer. 

The upcoming 4K DSLR could incorporate that if it were designed as a medium format and/or video competitor.


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## psolberg (Feb 23, 2012)

CrimsonBlue said:


> Jumping to 14-bit was a nice improvement, but for super-fast cameras, the amount of extra data passing through would reduce FPS without some other compensatory technology.
> 
> Medium format doesn't usually have more than a frame or two per second so it can process more data and not have to worry about filling/emptying a buffer.
> 
> The upcoming 4K DSLR could incorporate that if it were designed as a medium format and/or video competitor.



16bit color video @ 4K.. yeah, not happening.


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## Neeneko (Feb 23, 2012)

CrimsonBlue said:


> Jumping to 14-bit was a nice improvement, but for super-fast cameras, the amount of extra data passing through would reduce FPS without some other compensatory technology.
> 
> Medium format doesn't usually have more than a frame or two per second so it can process more data and not have to worry about filling/emptying a buffer.



This is a good example of why I have been grumpy at Canon lately. With the increased focus on framerate and video features, they are moving away from making stuff like this feasible. I would MUCH rather have a 16 bit camera then something designed for speed (AF,framerate,video,etc).


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## psolberg (Feb 23, 2012)

Neeneko said:


> CrimsonBlue said:
> 
> 
> > Jumping to 14-bit was a nice improvement, but for super-fast cameras, the amount of extra data passing through would reduce FPS without some other compensatory technology.
> ...



I agree. canon has been busying converting its customers into videographers...like it or not. I support a split. Put competitive video but focus on stills. go chase RED away from me.


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## Neeneko (Feb 23, 2012)

psolberg said:


> I agree. canon has been busying converting its customers into videographers...like it or not. I support a split. Put competitive video but focus on stills. go chase RED away from me.



This is kinda the cost of a 'runaway success'.. the 5D2 was so successful as a multimedia device, now anyone who wants to get funding for their department in any DSLR manufacturer has to explain how their design fits in to the 'obvious wisdom' of marketing.

Part of the problem though is customers tend not to realize just how much additional cost this type of feature ads I commonly here 'but you are getting video for free, just don't use it'. If more professional clients complained about the opportunity cost of the feature, Canon might listen more.


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## kubelik (Feb 23, 2012)

I wouldn't mind if the video were still 14-bit, but getting 16-bit stills would be awesome.


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## mitchell3417 (Feb 23, 2012)

I think if they were going to put 16 bit in the 5DX then they would have put it in the 1DX. If that tech was available they would have done it already. IMHO

Obviously bitrate is the biggest issue here. At 6.9 fps I don't see them squeezing 16 bits into the next 5d.

Someday though we will have 16 bit color. Just not this round.


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## sjprg (Feb 23, 2012)

YES! YES! 1 FPS is fine.


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## RedEye (Feb 23, 2012)

psolberg said:


> This is a good example of why I have been grumpy at Canon lately. With the increased focus on framerate and video features, they are moving away from making stuff like this feasible. I would MUCH rather have a 16 bit camera then something designed for speed (AF,framerate,video,etc).



I agree. canon has been busying converting its customers into videographers...like it or not. I support a split. Put competitive video but focus on stills. go chase RED away from me.
[/quote]

+1 for each of you, I agree. There needs to be a body that remains in the camera still photo business.


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## DavidRiesenberg (Feb 23, 2012)

I eagerly await true in-camera-HDR 32bit images. 8)


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## Neeneko (Feb 23, 2012)

DavidRiesenberg said:


> I eagerly await true in-camera-HDR 32bit images. 8)



Actually, I am thinking about getting MaxMax's B&W Canon just so I can do multi-shot pictures and combine them for nice bitdepth ^_^


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## marekjoz (Feb 24, 2012)

Is 14 bit only also not because of the noise? As I remember two lowest bits are just simply cut off because they are not useful in current dslr sensor technology - they are not able to provide 16 bits resolution.


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## Yoshiyuki Blade (Feb 24, 2012)

What else is bit depth good for other than simply increasing the amount of possible colors? More wiggle room to do fancy PP? It seems that 14-bit is quite overkill when monitors are in the 8-bit range, with high end pro monitors at 10 bit. And AFAIK, printed media don't reproduce a whole lot of color either. I mean, take a look at how much more color there is when you add 2 bits successively:

6-bit: 262K colors
8-bit: 16.7M colors
10-bit: 1.07B colors
14-bit: 4.40T colors
16-bit: 281T colors

If I understand correctly, bit depth increases the number of "steps" of color in a particular colorspace, but doesn't increase the breadth of colors (which depend on the colorspace itself). So you can have 16-bits of color in a tiny sRGB colorspace, which would be kind of worthless. However, for 16 bits in Adobe RGB, the steps are slightly larger and more dispersed well outside the range of sRGB. Is Adobe RGB even big enough to notice banding at 14 bits (since banding is the result of huge, perceptible steps of color in a color space due to insufficient colors)? Hard to know, that's for sure!

I think its too early to start talking about 16 bits considering how little we've actually seen beyond 8 bits lol


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## wickidwombat (Feb 24, 2012)

RedEye said:


> psolberg said:
> 
> 
> > This is a good example of why I have been grumpy at Canon lately. With the increased focus on framerate and video features, they are moving away from making stuff like this feasible. I would MUCH rather have a 16 bit camera then something designed for speed (AF,framerate,video,etc).
> ...



+1 for each of you, I agree. There needs to be a body that remains in the camera still photo business. 
[/quote]

Canon have proved they can make high res sensors, and have stated they can respond quickly to the D800 if needed although a little cryptic. I guess there must be a high res or two prototype banging around.
While I would be suprised if a high res camera that isnt the 1D would have 16 bit while the 1D does not who knows what they will do. Since ultra high res has no video benefit this high MP camera would be the perfect platform to forget about video and concentrate on stills the good ol 3D rumour  a high MP high dynamic range body with 1D build, no integrated battery grip low FPS super high quality low iso it will tick all the studio and landscape photographers boxes. 
A camera that is totally stills oriented would be refreshing and a high MP beast targeted at studio and landscape might just be the vehicle to deliver it. If they do i I just hope it doesnt have the integrated grip.

but what if canon made it and priced it at $5000? 1D build quality 2 or 3 fps 50MP super DR at iso 100 max iso 3200? then we would be flooded by crys of "how can canon do this to me its too expensive!" never mind that is half the price of a pentax 645D and can use all the canon glass you already have.

just some things to consider...


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## jrista (Feb 24, 2012)

RedEye said:


> If the technology has improved and the sensor pix count the same, is there any chance that it goes 16 bit color similar to many medium formats? Is a neat idea and the colors and contract could be stunning .



I find this question to be intriguing. For one, full 16-bit color would be great, if it was utilized. Ironically, despite Canon's claim of 14-bit color, they don't effectively use all 14 bits. To date, Canon's cameras score lower on color depth (DXO tends to rate Nikon/Sony cameras about 24 bits of color depth, to Canon's 21-22 bits). To date, Canon's cameras also score lower on dynamic range, maxing out at about 11.7 stops of DR, vs. the 13.9 stops achieved by Nikon/Sony cameras.

Personally, I would be ecstatic if Canon could actually produce REAL 14-bit RAW images that fully utilize each and every bit at their disposal, rather than gimping us by a full two stops on DR. From a color depth perspective, it certainly doesn't seem to matter a wit in real-world comparisons between photos taken by Canon and Nikon gear...but a difference of two stops of dynamic range IS something that can be measured, and gaining two stops of DR IS INDEED something that could be utilized...I could stop using my Lee .6 ND grad for most of my sunset/sunrise landscape shots. 

So Canon...please...please, please...give us TRUE 14-bit RAW, and TRUE 14-stop DR!!


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## marekjoz (Feb 24, 2012)

Guys, if you haven't read it... : http://www.clarkvision.com/articles/digital.sensor.performance.summary/ This is a great source of very deeply described camera sensor technology, based mainly on canon dslrs with physics fundamentals clearly explained and photo examples. It's a huge amount of information 23 pages long which clarifies why this all is it not as easy as we'd wish to.


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## Yoshiyuki Blade (Feb 24, 2012)

jrista said:


> I find this question to be intriguing. For one, full 16-bit color would be great, if it was utilized. Ironically, despite Canon's claim of 14-bit color, they don't effectively use all 14 bits. To date, Canon's cameras score lower on color depth (DXO tends to rate Nikon/Sony cameras about 24 bits of color depth, to Canon's 21-22 bits).



Wow, does that mean less than 8 bits per channel (with Nikon/Sony at 8 bits)? That's shockingly low! We could sit comfortably with our average 8-bit monitors if that were the case.


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## psolberg (Feb 25, 2012)

Neeneko said:


> psolberg said:
> 
> 
> > I agree. canon has been busying converting its customers into videographers...like it or not. I support a split. Put competitive video but focus on stills. go chase RED away from me.
> ...



it is easy to run away with the market when you were the only game that had a FF dslr with video. that's no longer the case. everybody is doing one and the really high end video is moving towards gear like the RED line or Cinema line from canon. I don't see the new 5D being the happy accident it was 3 years ago. If they make it better than their flagship and c300, it would just canibalize the market they are tying to go after. not going to happen.


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## sjprg (Feb 25, 2012)

16 bits have more to do with the tonal differentation than number of colors, as an anology think of a 100 foot ladder and the spacing between steps. Do you want 10 steps at 10 feet apart or 50 steps at 2 feet apart. I would hate to have to climb the one with the 10 foot steps.


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## TexPhoto (Feb 25, 2012)

I'd love to have 16 bit color, if the camera was actually able to resolve color to that level. But considering the bayer interpolation our sensors use to take color from the neighboring sensors (before the RAW image is recorded), I can't see the camera actually reading color to that depth.


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## Rav (Feb 25, 2012)

jrista said:


> Yoshiyuki Blade said:
> 
> 
> > Wow, does that mean less than 8 bits per channel (with Nikon/Sony at 8 bits)? That's shockingly low! We could sit comfortably with our average 8-bit monitors if that were the case.
> ...


I'm sorry to say, but your understanding of basically all concepts mentioned above is wrong.
- Bayer sensors have reduced _spatial_ color resolution, not color depth. 
- The bit depth determines the precision of the color information coding; how many distinct colors occur in an image is completely irrelevant. 
- The signal to noise ratio of a sensor sets limits to what a reasonable bit depth is. To justify 16 bits per channel, you'd have to have a SNR of at least 96dB, or 84dB at 14 bit. If that is not the case, your least significant bits statistically will only carry noise, i.e. wasted storage space.
- In post-processing higher bit depths make sense, to minimize color banding coming from the rounding errors inherent in integer math. 
- Bit depth does not influence saturation or gamut. However, the bigger your _color space_, the greater the need for higher bit depth to avoid banding artifacts.

As a sidenote, the human visual system also has a reduced spatial color resolution (and sensitivity) opposed to luma resolution, a fact that is exploited by the color subsampling (4:2:2, 4:2:0) employed by many compression schemes.


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## cgardner (Feb 25, 2012)

The rule of thumb, "If you can see it in the final output it matters, if you can't it doesn't" applies. Often technical differences don't translate proportionately, or at all, to changes in how the output is perceived. That's due in part because human perception of detail and color is the weakest link in the chain.

Back in the days when capturing in 8-bit JPG was the only option there was a noticeable problem with banding in narrow tonal variations such as skies due the the intermediate analog values of blue being pushed into one 0 - 255 RGB value or another. The problem was most evident in areas like sky where there was only one or two channels making up the color. RAW capture and 16-bit editing more or less eliminated that problem even before the bit resolution of the cameras at capture increased. 

I waited for bodies to reach 8MP before jumping to a DSLR system. I don't make many prints larger than 8.5 x 11 so that was enough resolution. The bits? They were what they were at the time. 

When I upgraded from my 20D to 50D there was a marked improvement in IQ, both in resolution and smoothness of gradients I could see in the output using the same capture PP workflow. Exactly way it occurred is less important to me than the fact I can see the difference, making the cost to upgrade the hardware. The pixels openings are physically smaller packing more MP into the same sensor size, but Canon cleverly changed the shape of the sensor wells so there volume and the sensor DR stayed similar. The DR of the 50D is slightly less, but not enough to notice. So overall however Canon managed to pull it off it works for me and improved the image quality I see on screen and prints versus what I had before, which in turn looked better than the results with my previous cameras. 

If I upgraded from the 50D I might see some minor incremental improvement in the type of things I shoot in the sizes I typically view and print them but not much. If I shot different content, like wall size prints of scenics, then my criteria and needs would be different. So baring dropping the 50D and busting I don't see the need for a new camera in my immediate future except for new features such as the planned switch to wireless controlled flash. What would motivate me to buy is a Canon body which could handle the contrast of a sunny cross lit scene like B&W can. But I'm not holding my breath on that one...


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## marekjoz (Feb 25, 2012)

The more bits - the more you can do in postproduction. The better SN ratio - the more bits you can have (what Rav has described). Signal to noise is the key to everything what is discussed here.


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## noisejammer (Feb 25, 2012)

Wish lists apart, we could look at the realities of sensor design...

I happen to have an 8-megapixel camera that I use for astrophotography. The pixels are 5.4 microns square and the well depth is iirc 25000 electrons. The camera readout noise is around 9.3 electrons rms and it's digitised to 16 bits. Keeping the noise down means that the camera can only produce 1 frame every eight seconds and it must be cooled to -25C. The camera has a quantum efficiency of about 50% over the visible part of the spectrum - this is very much better than CMOS devices.

So here's the rub - the resolution is sufficient to satisfy resolution for DSLR users - scaled up to 35mm terms it would be around 30 megapixels - but each pixel can only deliver a dynamic range of 25000/9.3 = 2700. This is equivalent to 11.4 bits. THAT'S HOW MUCH SIGNAL YOU CAN HAVE.... you can sample it using a 16 bit, 18 bit or 24 bit A/D, everything beyond 11.4 bits will be noise.

It's reasonably true that you can improve the signal to noise ratio by increasing the pixel area. Let's say you want a real 14 bits of signal, then the area would have to increase by 2^(14-11.4) = 6x. This would make the pixels around 13.3 microns on a side.... the problem is that you would only get 4.9 megapixels on a full frame camera. If you wanted 16 bits of signal you would get around 1.2 megapixels. 

Alternatively, you can suppress noise by cooling the camera further - there's a rule of thumb that cooling a device by 5 Celsius roughly halves the noise. Well this would work to an extent (but you could not go beyond about 14 bits because that's the well depth.) So be prepared to carry around a generator to power the cooling system that can bring the camera down to -35C

Of course, there's another gotcha... and this one is completely unavoidable. 

Because the camera can only store charge from 25000 pixels, it is only sensitive to the first 50000 photons that arrive. This makes it susceptible to photon noise too, and it turns out that this dominates everything. In practice, the camera which has an internal noise of 11.4 bits cannot achieve a signal to noise ratio that is higher than 223 - or slightly less than eight stops! I don't find this to be a problem - I did some tests on myself using a 10-bit monitor and I can't relieably perceive more than 7 stops either. If you have a calibrated monitor, you might want to try this yourself.

To achieve 14 bits of real data that you really need to record 28 bits of photons. Scaling the pixel area up by 6 bits (that's 64x) means that the pixels are now 43.2 microns on a side and your ff camera suddenly has only 460 000 pixels. Squeezing it to 15 bits and you need to limit the resolution to 115000 pixels and 16 bits would force you to have a spatial resolution of 26000 pixels.

And that is why we can't have a 16 bit camera. We can't even have a true 14 bit camera that's useful. Ever. It's sad, but Nature - in particular physics - is a harsh mistress.

If you want a larger dynamic range, try bracketing.
If you don't want to try bracketing, try a GND filter.
If you don't want to try bracketing or a GND, you're SOL. Sorry.


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## marekjoz (Feb 25, 2012)

noisejammer said:


> Wish lists apart, we could look at the realities of sensor design...
> 
> I happen to have an 8-megapixel camera that I use for astrophotography. The pixels are 5.4 microns square and the well depth is iirc 25000 electrons. The camera readout noise is around 9.3 electrons rms and it's digitised to 16 bits. Keeping the noise down means that the camera can only produce 1 frame every eight seconds and it must be cooled to -25C. The camera has a quantum efficiency of about 50% over the visible part of the spectrum - this is very much better than CMOS devices.
> 
> ...



What would happen if they successed to deeper the well depth beyond 25k electrons/per 5.4 microns square?


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## LetTheRightLensIn (Feb 25, 2012)

Rav said:


> jrista said:
> 
> 
> > Yoshiyuki Blade said:
> ...



+1
this


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## DavidRiesenberg (Feb 25, 2012)

For those that haven't seen it before, this is a great technical read on sensors:

http://www.clarkvision.com/articles/digital.sensor.performance.summary/


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## LetTheRightLensIn (Feb 25, 2012)

noisejammer said:


> It's reasonably true that you can improve the signal to noise ratio by increasing the pixel area. Let's say you want a real 14 bits of signal, then the area would have to increase by 2^(14-11.4) = 6x. This would make the pixels around 13.3 microns on a side.... the problem is that you would only get 4.9 megapixels on a full frame camera. If you wanted 16 bits of signal you would get around 1.2 megapixels.



I thought we already had some that deliver virtually 14bits (13.8-13.9) and that even the 1D4 sensor itself (before bad read electronics chop off a couple of stops or more) can grad 14+ bits if we are talking normalizing to 8MP equivalent....


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## cgardner (Feb 26, 2012)

Where I find the extra bit most helpful is in the post processing stage.

Most outdoor scenes exceed the range of the sensor and some very dark shadow detail is lost, but the brain of the viewer is easily fooled into thinking the range is fuller if the midtones and 3/4 tones are lightened beyond what the SOOC file shows by various adjustments at the RAW or CS5 stages.

The simplest way to see this is to open an outdoor shot exposed for highlight detail in Levels and move the middle slider left towards the shadows. A relatively minor tweek will produce a significant increase in the amount of detail the photo appears to have. The DR isn't expanded, but the brain looking at a photo with a 0,0,0 black and 255,255,255 white areas to anchor it's perception of the overall tonal range as being "normal" will equate any lighter shadow tones with detail even when there isn't any there. Surrounding an overall dark photo with a 0.0,0 mat has the same effect perceptually — 10,10,10 level tones will be assumed to have detail by comparison, at least in smaller insignificant areas of the photo. Photography is after all just an optical illusion, tricking the brain into recognizing 2D contrast patterns memories of 3D objects previously seen in person.

Back in the days of 8-bit workflow a Levels manipulation like that would often cause banding in the sky and other smooth gradients as a result of the original values being shifted — evidenced by gaps in the histogram depiction. But with thousands of data points per color vs. just 256 in a 16-bit workflow that same degree of manipulation doesn't result in any visible defects in the image.

Forcing the mid- and 3/4-tones lighter will amplify any inherent noise in the shadows but I address that problem in editing by apply NR to a duplicate layer then with a mask blend in the reduced noise layer in the shadows where the noise it noticeable. Since there isn't much important detail there to begin with in term of story content the loss of detail due it the NR doesn't have an net impact on the image — the more important information in the mid-tones and highlights remain the same, the viewer is just tricked into thinking a full tonal range was recorded.


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