Are my images Green?

Started 2 months ago | Questions thread
Stacey_K
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Re: You applied color space instead of converting.
In reply to Robin Casady, 2 months ago

Robin Casady wrote:

Stacey_K wrote:

Robin Casady wrote:

Stacey_K wrote:

And honestly, unless you really understand color space (and know why you really need a wider color space for a particular image), you're probably better off capturing and working in sRGB. Wider <> "better". For most images, even when used correctly, the difference is pretty subtle but the problems caused by incorrect color space use is not, as you have found out.

I disagree. Learning the difference between assigning a color space, and converting to a color space is not rocket science. Work in a wide color space; convert to sRGB when going to the web.

That is over simplifying the problems that can happen working even in aRGB, much less something like proRGB. A big one is VERY few monitors can display outside of sRGB and most can't even cover sRGB, so editing becomes a problem. You can't see what you are doing. You at least have to be checking for -out of monitor gamut- colors often to even have an idea of what is going on that you can't see.

Yes, but you can use gamut warnings. Using sRGB reduces your "elbow room" when adjusting colors, and limits your final results to the limits of your monitor.

If the device used to view the final image i.e. a normal monitor has this same limit, why create colors that can never be viewed? Now if you have a good printer and are controlling the printer profile etc -and- know you can actually print outside of sRGB, then sure, for that output aRGB makes sense. For most people, it doesn't. It's why I tell most people, use sRGB unless you really understand why you -need- something else.

And as far as sRGB vs aRGB, most of the extra room in aRGB is in the green to cyan colors. You get a -little- extra in the others. Not enough in my experience to be earth shattering.

And you should always have the RAW file to go back to if you find you can use a wider color space for -that- image.

Also, as the color space becomes wider, the chance of posterization increases.

Explain this to me, please. My understanding was that posterization was caused by the limited colors available in 8 bit color. As a sky or other area of subtle color/value change is rendered the 256 colors in 8 bit are not enough to make a smooth transition.

Correct. And the same thing can happen when you start using a really wide gamut color space, even when you have more bit depth.

Lets assume for example, in each color channel you have 0-255. In sRGB given the color space is smaller, each step is fairly close to the next so going from 125 to 126 is almost imperceivable. Now we go to a really wide color space like proRGB, each step has to be much larger to be able to cover this much real estate, so now going from 125 to 126 is more noticeable. You are likely to never use anywhere near to whole color space, so when you convert to a smaller profile, you still leave these larger steps between colors.

This page explains this phenomenon well, scroll down to "Bit Depth Distribution". This site does a nice job explaining color space in general IMHO.

http://www.cambridgeincolour.com/tutorials/sRGB-AdobeRGB1998.htm

Working with 16 bit per channel makes this less of an issue and probably is not an issue with 16 bit aRGB. For someone like me who likes to use OOC jpegs if possible, sRGB makes sense since these are 8bit per channel and some do need slight color adjustments. I still would question using proRGB for most images no matter what the bit depth for this reason.

I'm not 100% on this next statement but I'm thinking if you do work in 16bit aRGB and plan to display the image as an 8bit sRGB jpeg image, you should convert the image to srgb -before- you reduce the bit depth.

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Stacey

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