I wasn’t sure if I should begin with walking through how to deal with 3D renders or with Photoshop.
I decided it was more logical to start with Photoshop, as that’s where most renders end up, and having Photoshop under control helps understanding the 3D part later on.
I’m working with Adobe Photoshop CS4, but the color management hasn’t changed that much in the latest versions, so it should work more or less the same in previous versions as well. Let’s start by setting up Photoshop’s behavior. Edit » Color Settings brings up this dialogue window. This is where you define Photoshop’s default behavior.
In the Working Spaces section you can select your default color spaces. I never use CMYK or Spot, so let’s focus on RGB and Gray. I usually work in ProPhoto RGB or Adobe RGB, but I’ve still selected sRGB as my default working space – remember this is just the default behavior and any document with an embedded ICC profile won’t care about this setting but open in the correct space it’s tagged for and the working space doesn’t come into play at all. By having sRGB as my default space, new empty documents will default to it though. Most of the time when I start with an empty canvas in Photoshop it’s for texture map painting, and then I want to be in sRGB as that’s the color space most 3D applications assumes the image will be in. So that’s the reason why I keep it as my default.
The same goes for Gray, I’ve set it to Gray Gamma 2.2, as that matches my monitors gamma and lets me see the correct gray levels when working, and I usually use the gray mode in Photoshop when painting bump/specular/subsurface scattering textures and such, and then that’s the appropriate setting to use. (I believe it’s originally set to dot gain, which is for print work).
Color Management Policies
In the Color Management Policies section you can decide how Photoshop will handle documents with existing profiles and when you want to be alerted. I’ve selected that I want to Preserve Embedded Profiles, because when I open an image that I’ve been working with in ProPhoto RGB for instance, I want it to stay in that color space the next time I open it as well. This is the most sensible option to use.
Then you have a few checkboxes, which lets Photoshop know when you want to be alerted. On Profile Mismatches I have Ask When Opening unchecked. If it were checked Photoshop would ask me every time I open a document which isn’t tagged for sRGB if I want to convert it to sRGB (my default color space) which would be extremely annoying – as most of my images aren’t in sRGB. So let’s keep it unchecked. Ask When Pasting between documents with different color profiles I keep checked though, as that’s pretty handy to be able to keep colors, especially when using photos shot in Adobe RGB for texture maps that are created in sRGB. With this option checked I can choose how I want the colors to be converted to the smaller gamut. Very handy.
The last checkbox, Missing Profiles, I keep checked. All renders coming from a 3D application is untagged and does not contain an ICC profile, and would look wrong if not the appropriate profile where assigned to it (the default space of sRGB is not correct if you have been working on a wide gamut screen – more on this later). So when opening an untagged image from a 3D render Photoshop asks what profile I want to assign to it, so it can enter the color managed workflow from that point.
That’s it for Photoshop so far, let’s move on…