Photoshop Greyscale Color Settings - Metal, Gloss, etc.

[cjwidd]

Reset Photoshop recently and I can't recall what the go-to settings are for working with greyscale PBR maps (e.g. metalness, glossiness, roughness, etc.). I almost always import these maps into Max without automatic gamma correction (e.g. Override 1.0).

What is the correct color setting to select from this menu to maintain consistency with the import workflow as I've described it above - to maintain visual consistency?

[Juraj]

If it's integer 8/16bit file format (effectively every 8&16bit format except for 16bit .exr which is floating point with linear gamma) then you have to use manual gamma override for B&W maps that were authored to be used as linear (.ie roughness, metalness, etc... ). 3dsMax would otherwise read them as 2.2, which they effectively are.

Truth be told, integer files have embed gamma 2.2 for most part, so it's strange how industry wide standard is to use them to hold files in linear gamma. We really should be using .exr for absolutely everything, at least when gamma 1.0 concerned.

Default Photoshop gray-scale is Dot Gain 20 perc. It's purely printing profile related, it shouldn't affect anything at all. Once again... the file format sucks for the intended purpose of linear map :- ).

Did you find memory savings with grey-scale files in 3dsMax? I thought it never worked properly, and I burned myself with buying TexturesXYZ which has grey-scale 32bit. TIFF that 3dsMax can't even read. (And why the hell did they even use TIFF again for 32bit files? It is one of linear floating point files, but it's so rare to use... .exr all the way).

[cjwidd]

If it's integer 8/16bit file format (effectively every 8&16bit format except for 16bit .exr which is floating point with linear gamma) then you have to use manual gamma override for B&W maps that were authored to be used as linear (.ie roughness, metalness, etc... ).

Right, that's what I'm getting at, but which of these numbered options achieves that?

[Juraj]

None? That's just Photoshop asking you what working color profile do you want to use. The default is already in the middle radio (Dot 20).

What does it have to do with gamma loading in 3dsMax?

[pokoy]

I think the standard factory setting is dot gain 15%.
As Juraj says, profiles are for viewing only and don't affect max at all, they are completely ignored in max (unless max gets color management at some point).
As for consistency, I'd leave it at standard 15% so you get consistent display for all greyscale files you work on.

And yes, the all probably have gamma 2.2 baked in, and I'm not even sure if displaying linear would be good as colors/tones would display too dark anyway.

What's important is that you never convert on open as this will change the actual pixel *values*.

[cjwidd]

What's important is that you never convert on open as this will change the actual pixel *values*.

^I think this is what I was getting it. I remember reading on the forums that if you open a 32-bit (linear) .HDR in in PS and save, the save operation will basically ruin the .HDR because PS clamps pixel values at some threshold.

I don't want to open a linear 8bit, 16bit texture in PS for editing, make a bunch of changes to the texture, save it, and then bring it into Max only to discover that I actually f*ed up the texture due to some gamma correction / color profile that was applied automatically or incorrectly at the time of opening, or saving, in PS.

Does that make sense?

[Juraj]

32-bit (linear) .HDR in in PS and save, the save operation will basically ruin the .HDR because PS clamps pixel values at some threshold.

I have tested this and never found it to be the case in normal usage. I understand where this sentiment comes from, for example PS's 16bit mode is actually 15bit (and shifted?) because they wanted the operations to be faster... 20 years ago and the legacy is still there.
While it might cut some values off, I believe those values are far out of any usable range for Sky domes or Displacement values. It definitely doesn't affect any Sky Domes I've tested.

But it's better to use .HDR than .exr if you have truly large dynamic range (HDR supports up to 256 stops).

But that is talking about dynamic range of floating point linear files. 8 & 16bit Integer files have zero dynamic range. The unsigned values are simply 0 to 255 and 0 to 65635.
So if Photoshop cuts off some values at 16bit range, we're talking unperceptible difference in precision.

Everything Pokoy wrote is correct, but default dot gain is indeed 20 perc. you can reinstall Photoshop or simply choose North American General Environment to check :- ). Not that it affects anything you ask about.
And yup, the larger issue is baked in gamma correction. But that has nothing to do with Photoshop. Using integer files with baked gamma was simply never good choice for anything outside of pure B&W masks.

If you need to modify these types of files, convert them to 32bit environment in Photoshop first (even if you plan to save to 16bit .exr, since that is associated with 32bit linear environment only with half the precision) and then make any changes.

[pokoy]

20% dot gain, really? Oh I'm getting old, these things used to be hardcoded into my mind :D

Yes, as long as you don't convert, the profile will only affect display in PS or apps that care about embedded profiles (if no profile is embedded, it'll default to system standard). Since max doesn't, you're safe to use whatever works best for you.

[Juraj]

Max is kinda of weird with color profiles.. I am not sure if it ignores them completely, at least in regards to textures. With bitmap having no color profile attached, it acts as sRGB. But I loaded once AdobeRGB texture and it did appear more saturated (visible only when monitor is set to wide-gamut since, since 3dsMax does ignore system-wide ICC profiles).

I am currently not using wide-gamut monitor, otherwise I would do comparison with Vray's ICC node to see what 3dsMax actually does by default.

[pokoy]

I have a wide gamut hardware calibrated display and max ignores any embedded profiles, displays the windows default so it's 1:1 with the new win10 image viewer, which also ignores embedded profiles.

[Juraj]

I would like to test this but I am talking purely bitmap color profiles, of course 3dsMax ignores any ICC profiles so the colors look wrong unless the Monitor is clamped through OSD profile LUT.

I tested this (it was 6 years back) on saturated red color, one that could have been outside of sRGB but I don't remember sadly (since that makes a lot of difference for this test)...
My setup was following:

My wide-gamut display at that time (Dell 3011 I believe) was set to wide-gamut AdobeRGB in Monitor OSD, Windows was set to corresponding AdobeRGB profile as well.
Thus, everything color managed in Windows like Photoshop displayed wide-gamut colors correctly, and 3dsMax oversaturated everything because it stretched its native sRGB value into AdobeRGB interpreted by monitor.

I authored the bitmap of red-color into TIFF with sRGB and AdobeRGB color profiles (Two textures). I loaded them into 3dsMax and they displayed differently.

To test this thoroughly I would need to test it with 4 sets of textures like this:

a) sRGB color bitmap with sRGB color profile
b) sRGB color bitmap with AdobeRGB (or DCI-P3 nowadays) color profile
c) Wide Gamut color bitmap with sRGB color profile
d) Wide Gamut color bitmap with AdobeRGB (or DCI-P3) color profile.

And of course, test in Vray with ICC correction in framebuffer. Since I want to discount how colors are displayed, just want to know exactly the kind of interpretation 3dsMax bitmap loader does.

Because I don't believes it ignores/strips them, but rather assigns sRGB automatically, making wide-gamut input impossible without nodes like VrayICC for wide-gamut bitmaps. Which is then of course stretched when displayed because it doesn't respect any ICC correction.