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16 bit files

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  #1  
Old 11-15-2014, 01:32 AM
shoreboy shoreboy is offline
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16 bit files

Is it standard practice to work on 16 bit files?
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  #2  
Old 11-15-2014, 07:17 AM
skoobey skoobey is online now
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Re: 16 bit files

If that's your standard, yes. 8,16,32 are all widely used.

16 is the most common for published work, yes.

It's about knowing what you need, and not wasting time on 16 when noone is going to know the difference, or knowing that you need that 32bit on some composite work in order no to clip things etc.
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Old 11-15-2014, 12:29 PM
shoreboy shoreboy is offline
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Re: 16 bit files

Thanks for the informative answer.
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Old 11-15-2014, 12:50 PM
redcrown redcrown is offline
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Re: 16 bit files

Lot's of info and debate out there. Here are 3 from my bookmarks:

http://www.digitaloutput.net/content...ntCT.asp?P=350
http://staging.digitalphotopro.com/g...-decision.html
http://www.creativepro.com/article/o...-bit-advantage
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Old 11-15-2014, 01:57 PM
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Repairman Repairman is offline
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Re: 16 bit files

If you are working on an industrial strength Mac I would work 16bit as the larger file size won't make too much difference to your speed. 50% of the images I work on come from Maya as 32 bit RGB files; they invariably go out the door as 8bit CMYK. The differences in quality are easy to spot but that is only by comparing two images side by side - not something the end viewer will be able to do or care about. Looking at 16 and 8 side by side will show up differences in tonal integrity but it is very much case dependent. I would archive as 16bit basically to futureproof the file - could be that those subtle but significant differences will be easier to appreciate in print or digitally further down the line.
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Old 11-15-2014, 02:34 PM
skoobey skoobey is online now
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Re: 16 bit files

Lemme put it this way:

You're working a 20$ an image quick catalog/web retouch, you're doing it at 8bit and forgetting about it. Same for the model test, portrait for print that is quater of the page or smaller...

You're doing a campaign with plenty of DNB, you want those extra bits.
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Old 11-15-2014, 08:54 PM
klev klev is offline
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Re: 16 bit files

Quote:
Originally Posted by Repairman View Post
If you are working on an industrial strength Mac I would work 16bit as the larger file size won't make too much difference to your speed. 50% of the images I work on come from Maya as 32 bit RGB files; they invariably go out the door as 8bit CMYK. The differences in quality are easy to spot but that is only by comparing two images side by side - not something the end viewer will be able to do or care about. Looking at 16 and 8 side by side will show up differences in tonal integrity but it is very much case dependent. I would archive as 16bit basically to futureproof the file - could be that those subtle but significant differences will be easier to appreciate in print or digitally further down the line.
I want to point out that those 32 bit files are fundamentally different in their encoding. A conversion in photoshop from 8 to 16 bits can be done with a simple zero extension. Other than that it's organized in the same way. Maya outputs 32 bit files in a floating point encoding and gamma 1.0 space. To use ICC profiles, you are restricted to v4 types for this kind of encoding. It also handles a much wider range with the typical 0-255 converted to 0.0 to 1.0 with an actual range of plus or minus a very large number. Depending on the color engine, you have to be careful when converting between color spaces there, as some of them will clamp at unexpected stages.

I've expected to see more raw converters go that way for years. I mean you do have some rounding as floating point math is different in the sense that not every number in its range is a part of its domain, but it's viable with a stable math library and 32 bit encoding. We just need more packages to support a full set of tools in that encoding, which unfortunately means a much more significant rewrite than what it took to go from 8 bits to 16.
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Old 11-16-2014, 01:41 AM
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Re: 16 bit files

Can you put that in layman's terms Klev!
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  #9  
Old 11-16-2014, 10:51 AM
klev klev is offline
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Re: 16 bit files

There are probably two major differences that would be of interest to you.

The first is that each time the value doubles, the brightness doubles. The second is that you have a much much wider range of values that can be stored. Instead of 0-255, the equivalent range is 0.0 to 1.0, but it can store values in excess of 10.0 or -10.0 assuming you don't make any changes that force it to clip anything outside of the 0 to 1.0 range. I don't have a full list of actions that force that. For example you have to test profile conversions, as different color engines deal with these things differently.

When I mentioned ICC v2 vs v4, they're both ICC profile types. v2 are the older ones, which cannot be used in photoshop's 32 bit mode. Maya uses something that they refer to as linear sRGB, and I see the name come up quite a bit. I haven't been able to find a standardized representation of it. Anyway just like with other profiles, these things are converted to a form suitable for viewing on screen.

I guess the thing that's really interesting is you should have some ability to bring back blown highlights and things if you receive a 32 bit file that wasn't set to clamp anything that fell a couple stops out of range. Some color correction tools also offer a lot more flexibility, and they could design dodge/burn tools that would also offer greater flexibility. By the way clamp = clip for all practical purposes.

Some software has also started to implement or implemented linear tools for painting. There's sillouette fx, and I think Krita has some on the open source end. The OSX version is still basically alpha software, but I want to contribute to it if I get the time. I've said for years that Adobe should go this route.

Regarding raw files you could basically dump the full range of that file from lightroom into photoshop still in Adobe's linear prophoto space (prophoto isn't ideal, but it's what they use) without converting to a narrower gamut and clipping anything out of range. If you combined that with some of the newer edge finding algorithms that have surfaced in the past five years or so (ironically microsoft research has contributed to this), you could get a really nice balance of contrast and details. I don't really care for the typical cartoony HDR thing, but you just gain so much more control with such a workflow.
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Old 11-16-2014, 11:43 AM
skoobey skoobey is online now
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Re: 16 bit files

Or even simpler...

It's all number of combinations 8bit has 256 different lightness values for R, G and B.

16 bit has 65536.

32bit has 16777216.

Just an example, I know it's not real thing that you can see, and that it depends on the actual color profile blah blah.

But, what does this mean? Well, in reality, it means smoother transitions when you start pushing pixels.

So, a curve applied to something smooth like a sunny sky in 8 bit might leave you with a posterized looking result.

16 bit bit file, when affected by the same curve will be much smoother.

And 32 bit? Well, it won't even clip where the 16 bit clips, meaning if you blow something out, and than do an opposite adjustment, it might just bring it back. Why? Because there is more tonal differences.
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