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Old 03-14-2012, 02:38 AM   #1
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same color profile but diffrent image between Maya/PS

When I save a TARGA image from the render view in maya, (Image Color Profile & Display Color Profile set to sRGB, maya’s default v alue) and open it in Photoshop, the image is a bit different as if Photoshop is set to a different color profile, but I double checked and it’s set to the same sRGB color profile, why is that?
*If I set the maya’s “Image Color Space” to HDTV (Rec. 709) then it looks like the same image in photoshop, but this is weird because as I said, the color profile is set to sRGB and not HDTV (Rec. 709).
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Old 03-14-2012, 06:14 AM   #2
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I'll repeat this here for people to see:

Quote:
Image Color Profile & Display Color Profile set to sRGB


This is wrong, your Image Color Profile should be Linear sRGB. Display should be sRGB.

Photoshop tries to read the ICC embedded profile of an image, if the image does not have one, it will default to sRGB IEC 61966-2.1, this should be very close to your sRGB inside the Maya display window. (In my case the image (Targa) in Photoshop matches the Maya Render View close enough that I cannot tell a difference with my eye. My monitors are calibrated.)

In Photoshop, HDTV rec 709 is the same colorspace as sRGB IEC 61966-2.1 visually (same white point and chromaticity) but sRGB specifies a specific gamma of 2.2 for viewing while rec 709 has a destination of 2.4 for viewing. Chances are your monitor is not set up as rec 709. If you change to rec 709 16-235 it remaps the luminance for broadcast, your blackpoint is now 16, not 0 and it will look darker. High values are mapped from 255 to 235.

When viewing in Maya, have your Image Profile set to Linear sRGB and do not use a lens shader. Then you can make your Display whatever colorspace (and LUT) you need to view it in, this is correct linear workflow. (Meaning your source image and render are linear.)

I try not to let Photoshop color manage my documents if I can help it.
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Old 03-14-2012, 02:07 PM   #3
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Quote:
Originally Posted by Bitter
This is wrong, your Image Color Profile should be Linear sRGB. Display should be sRGB.

what's the difference between Linear sRGB and sRGB?

Quote:
Originally Posted by Bitter
do not use a lens shader.

what's wrong in using a lense shader with a gamma of 2.2?
after years of experience i can tell that it is the safest way for physical correct workflow

Quote:
Originally Posted by Bitter
When viewing in Maya, have your Image Profile set to Linear sRGB and do not use a lens shader. Then you can make your Display whatever colorspace (and LUT) you need to view it in, this is correct linear workflow. (Meaning your source image and render are linear.)

if i set image color space to linear sRGB and display color space to sRGB with no lense shader, the image becomes dark and super grainy and even more different in PS?
Quote:
Originally Posted by Bitter
I try not to let Photoshop color manage my documents if I can help it.

completely agree here, no issue with maya/after effects
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Last edited by royterrrr : 03-14-2012 at 02:17 PM.
 
Old 03-14-2012, 03:01 PM   #4
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linear sRGB is the sRGB colour space but without the 2.2 gamma.

You might want to look into creating a 3D LUT for Maya if you have Nuke. That's how I calibrate the two apps and I use the generated .cube LUT with V-Ray's VFB to calibrate it with Photoshop:

http://polygonspixelsandpaint.tumbl...post/3684476660

this also gets into it:

http://polygonspixelsandpaint.tumbl...post/9547388794

Last edited by cgbeige : 03-14-2012 at 03:04 PM.
 
Old 03-14-2012, 05:57 PM   #5
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Quote:
what's the difference between Linear sRGB and sRGB?


cgbeige is correct, Linear sRGB is linear space, but the primaries are still sRGB (no color shift)

Quote:
what's wrong in using a lense shader with a gamma of 2.2?


The lens shader was necessary when there was no way to preview correctly in Maya. But now you can. Look here for an explnantion of the preferred workflow for Maya: Linear Workflow in Maya

Quote:
if i set image color space to linear sRGB and display color space to sRGB with no lense shader, the image becomes dark and super grainy and even more different in PS?


If you are using sRGB for image colorspace AND a lens shader, you are double correcting the sRGB and washing out your scene. Chances are if you're doing that your workflow is already incorrect and your image is washed out by default. Look at the images at the end of the blog post I posted above for an example.
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Old 03-15-2012, 02:25 PM   #6
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I noticed that too when I open a image, photoshop alter the colors a little.
In edit > Color Settings > altering the RGB working space affects the colors
 
Old 03-15-2012, 04:34 PM   #7
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Quote:
Originally Posted by Bitter
If you are using sRGB for image colorspace AND a lens shader, you are double correcting the sRGB and washing out your scene. Chances are if you're doing that your workflow is already incorrect and your image is washed out by default. Look at the images at the end of the blog post I posted above for an example.

The image is darker and grainier even if i delete the lense shader.

i wan to try your method but don't have nuke, is it possible ti linearize a texture in PS?

BTW here is my workflow, and it worked without any problem:
1-gamma correct color textures and maya color swatches.
2-use a lense shader with gamma 2.2
3- render a 32 bit image
4-edit in after effects after setting the project to 32 bit.
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Last edited by royterrrr : 03-15-2012 at 04:48 PM.
 
Old 03-16-2012, 01:01 AM   #8
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When you render to the lens shader at 2.2 you are no longer rendering a beauty to a linear image. You are rendering it back to sRGB gamma and baking the 2.2 into the image. If you save that beauty with the 2.2 baked in and take it to AE and AE assumes 32-bit is linear (which it does I think) then it corrects it again and you're getting another 2.2 gamma on top.

Framebuffer Passes output with a lens shader will still be linear. But the beauty pass will have the gamma baked in with a lens shader, make sense?

Remove the lens shader if you are using the beauty pass, this will leave it at gamma 1.0 (linear) Then take it into AE and correct it to sRGB there.

Use the method outlined in the blog with the Maya Render View Color Manager to view it in sRGB without having to add a lens shader. This way you are not baking a gamma into the beauty image.

A linear image will correctly be darker than an sRGB image. LINEAR:



Linear images will appear dark and possibly grainy, but VIEW it correctly like below and it will look correct. Once corrected in AE it will look like this:



The beauty you are using STARTS at the above state with 2.2 baked in to the beauty pass. In AE or Photoshop it is probably correcting it again (32-bit assumes linear and it doesn't know you baked in the gamma) Looks like this now:

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Last edited by Bitter : 03-16-2012 at 01:04 AM.
 
Old 03-20-2012, 09:16 PM   #9
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Quote:
Originally Posted by Bitter
Remove the lens shader if you are using the beauty pass, this will leave it at gamma 1.0 (linear) Then take it into AE and correct it to sRGB there.

This is what i used to do. I used to work with a 2.2 gamma lense shader (all texture gamma corrected) then before the final render, i used to delete the lense shader and render a 32 bit image, open it in AE and apply a 2.2 gamma but there were always a slight difference that used to bug me. Until i discovered by accident that leaving the lense shader and rendering a 32 bit image give the same result as in Maya (no difference) plus i had the advantage of working with an hdr image witch applied AE effects like for example glow more elegantly.
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Old 03-20-2012, 09:16 PM   #10
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