Hi, I’m using a Greyscale image for specular and am getting some strange results.
I know it’s best practice to use Color Space: Non-Color for textures that don’t use color.
Although my image is black and white, I’m getting better results when using Color Space: sRGB than Non-Color
Specular sRGB:
Specular Non-Color:
Principled Shader:
Any idea why this is happening? Thanks.
Generally a specular map is non-color… yes… it’s a controlling map for specularity… just stored as an image because this format is already readable by the graphical engine… maybe evne further changed by any curve… but if the maker of it also used a color management… then it maybe better to use this too… different artist and/or different platforms does this… well differently…
This is also the reason why sometimes it is difficult to use assets when you have to build up the shader for a different rendering engine… even sometimes for pros… that’s also the reason of all the different tips and tricks and factual opinions (sometimes propagated over years from different “tutors” who maybe not really know what they are doing bit also just saw it on any video platform you like ??) and almost religious wars…
If you are happy… than have fun… 
But if image is greyscale, why would it show better results when using sRGB opposed to non-color?
“Better” is a subjective term- there’s not a mathematically precise interpretation of the term, just whatever you think looks better. There’s a decent chance that non-color actually gives a more accurate result to the original data, but sRGB looks better artistically
You yourself discovered: a different color model changes the grey values at specific areas…
So… it is different… there is no why… 
Not going into too much details here but sRGB modifies the linear red, green and and blue value sto be “closer” to eye perception and hardware presentation ( actually old CRT monitors… so it may not be closer now )… so a greyscale has the same values in RG and B but is altered as “color” differently per channel (it’s not as in HSL/HSV where the grey would be in the L/V value and the saturation would be zero). So again it is different here…
