<QUESTION: I'm choosing to use sRGB IEC61966-2.1 as my working color profile in AE. When I select this profile, the AE project colors immediately appears a little washed out. I add an adjustment layer to the final project and adjust the contrast, brightness and a couple of other color teaks to make it look the way I want in After Effects. Then I render it  and the resultant video looks completely wrong, with around 15% more contrast, and over-saturated.

Sometimes I think AE color management should be renamed "Color MANGLEment". LOL. The problem you’re describing relates specifically to either GAMMA or BLACK/WHITE levels.

Much video is not fully "color managed" in most player applications, and despite the fact that Apple does allow for embedding ICC profiles in Quicktimes, After Effects (at least as of CS5.5) does not allow embedding the ICC profile, meaning the video clip you render out will not be color managed when played. (Not certain of CS6 will allow for embedding in QTs.)

I rarely use AVI, so I can't speak to it's specific quirks, 

SCENE REFERRED vs OUTPUT REFERRED.

Charles Poynton relates the situation in detail here:

http://www.poynton.com/notes/PU-PR-IS/Poynton-PU-PR-IS.pdf

But here is a quick "nutshell" of the situation, using HDTV as the example.

HDTV tech specs define a SCENE REFERRED profile for program material. THis profile defines the primaries, and also a gamma curve that is somewhat close to 1.9. This profile is called REC709.

The Rec709 scene referred video (gamma 1.9) is pumped into a display (gamma 2.4) and you get a *system gamma boost* of roughly 1.2

The system gamma boost is there intentionally, so that a scene referred HDTV Camera, shooting a scene in daylight, will be "perceptually the same" once it is displayed on a screen in a darkened living room.

sRGB is an OUTPUT or DISPLAY REFERRED profile. It uses the same primaries as Rec709, but has a slightly different gamma curve, that is approx. 2.2.

Note that sRGB, an output referred profile, specifies a gamma of 2.2 instead of Rec709's lower 1.9, because sRGB was developed and intended for computer monitors, which are used in a brighter work environment, as opposed to a dark living room viewing environment.

BOTH sRGB and Rec709 are assumed to be displayed on a monitor with a power transfer factor of around 2.4. sRGB's transfer function in intended for brighter viewing environments.

16/235 vs 0/255

Another critical issue is the black/white levels. Does your codec expect them to be 16/235 or 0/255? Some video players may not interpret one or the other correctly. And some encoders may force the video into 16/235 even if you are sending it 0/255.

Broadcast Rec709 has the black set at 16 and the white set at 235 for both RGB and YCbCr. If you try and send 0/255 into this system, you will have your blacks clipped and too dark, and the whites clipped or too bright.

WHICH SHOULD YOU USE ?

Working Profile

As Darby indicated, your working profile is not the critical problem here. Choosing the best working profile is another topic entirely, but in a nut shell, choose a profile that contains all of your colors without clipping. Larger profiles such as ProPhoto *require* the use of high bit depths (i.e. 32 bit). If you are headed for the web or for HDTV, then sRGB is often a good choice - but only for your WORKING profile.

Output Profile

If you were going to play back your video in a COLOR MANAGED player and you had embedded your profile in the video media, then it would not matter what output profile you chose, as the player would manage it and display it appropriately.

HOWEVER, as we said at the start, video is typically not color managed for the purposes of distribution. (You may notice that "Embed Profile" is greyed out when using most output modules in AE). And besides, if you cannot control how people are viewing, you'd want your video to play correctly in non-colormanaged environments.

So, that means that we must choose an output profile in After Effects' output module that creates a video file with the kind of color/gamma that the PLAYER application EXPECTS to see.

And what would a player application usually expect? TYPICALLY A SCENE-REFERRED VIDEO STREAM.

Since sRGB is an OUTPUT referred profile, it is "generally incorrect" to use to output your video if you are sending your video someplace that is expecting a scene referred profile such as Rec709.

However, Adobe FLASH expects sRGB, so the implication there is to use sRGB as the output profile, and that is what the flash environment *expects*.

But most player apps are expecting either Rec601 OR Rec709. As a result, Rec709 is usually the choice for a video outpu

And Then the 16/235 thing:

Now, as it happens, different codecs and different player apps may handle the 16/235 and 0/255 and gamma issues differently. Some do not correctly interpret the correct black/white levels.

Since I don't use the AVI container much, and don't which which variant of "uncompressed" you are using, I can't say definitively - BUT from what you describe it sounds like you are outputting to a 0/255 black/white point colorspace (sRGB), and the codec & player you are using wants to see a 16/235.

So do this: TRY USING the colorspace: Rec709 16-235 as your OUTPUT colorspace in the output module. Note that while Rec709 has a lower gamma (which increases contrast for darker environments) than sRGB, using the 16-235 variant should fix your black levels if this is what the codec you are using is expecting.

Here are some links with some discussion on scene vs output referred colorspaces, gamma, and color:

scene_vs_display_referred_profiles

http://www.poynton.com/PDFs/GammaFAQ.pdf

This little tidbit from page 6 of the gamma faq:

Ambient lighting is rarely taken into account in the exchange of computer images. If an image is created in a dark environment and transmitted to a viewer in a bright environment, the recipient will find it to have excessive contrast.

http://www.poynton.com/PDFs/ColorFAQ.pdf

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