Difference in brightness Corona VFB vs Photoshop

[Juraj]

I wrote probably 20 essays on this topic on this forum, but currently 3dsMax, and Corona, still ignore system color profile (which is mostly ICC).

Yeah I'm mostly going on your response from here

Yeah, nothing really changed sadly. It's funny how such basic thing can be ignored by Autodesk :- ). Looks like it will have to be done by Corona, just like Vray just did it (together with big OCIO package integration).

Interesting thing is, that the issue is now quite popular. Previously only 1000+ Euro monitors were wide-gamut, but right now almost every 200+ monitor is. Even if it's just 105perc. of sRGB, it's 5 more then necessary and thus non-color managed applications (those that ignore system color profiles) show wrong results, i.e games.

Gamers are the people who demanded hardware clamping (Monitor OSD profiles) the most, without it, every game looks wrong (oversaturated).

It will be very funny if computer games become color managed faster than Autodesk software lol! Which they probably will because of ubiquitous rise of HDR displaying.

[Juraj]

Reminds me how Microsoft, with million employees, can't integrate simple essential feature like "tabs" into file browser. It's been in alpha testing for 6 years :- D. I have to use commercial plugin for stupid shit like that.

[cjwidd]

Posting a video to *try* and illustrate the issue as I am experiencing it - it is difficult or impossible to illustrate these types of color management issues because of monitor-specific color space differences, but I've tried to describe the visual difference in basic terms for the sake of comparison. Watch x1.5-2.0 speed.

[cjwidd]

Reminds me how Microsoft, with million employees, can't integrate simple essential feature like "tabs" into file browser. It's been in alpha testing for 6 years :- D. I have to use commercial plugin for stupid shit like that.

Posting just to lol bcuz it's true

[cjwidd]

So basically a monitor-specific color profile is being applied to the display, e.g. Dell.icm.

The image in the Corona Renderer VFB is modulated by Dell.icm

To achieve parity between Corona Renderer VFB and Photoshop:
*PS color settings should be set to ask about color space on open, e.g. profile mismatches: ask when opening / ask when pasting; missing profiles: ask when opening
- Image.exr -> right click -> Open in Photoshop
- Assign profile: Dell.icm
- [check] and then convert document to working RGB
*working RGB should be sRGB IEC61966-2-1

What about CTRL+C VFB to Photoshop?
- Photoshop -> New -> Advanced Options -> Color Profile -> Dell.icm
*document must be converted to sRGB IEC61966-2-1 on export, or before, i.e. Photoshop -> Edit -> Convert to profile -> Working RGB: sRGB IEC61966-2-1
*or, Export As -> Color Space -> Convert to sRGB

[cjwidd]

5 years ago, repeating history

[pokoy]

An idea, you can use VFB+, it has support for ICC profiles, and the best thing is it's free.
It won't work with IR but it will take your Corona VFB output on render end and display it the way you would see it in Photoshop when the same profile is specified.

The problem won't be solved unless Max finally has some sort of color management. Autodesk is going for OCIO which recently got support for ICC, but who knows how long that will take to be incorporated into Max.

Corona could also add support for ICC profiles just like VFB+.

[cjwidd]

According to Adobe Bridge metadata panel:

Exporting an .EXR from the Corona Renderer VFB (3ds Max) produces a sRGB IEC61966-2.1 (linear) image.
Exporting a .PNG from the Corona Renderer VFB (3ds Max) produces an untagged image.

• The .PNG image appears identical to VFB when viewed in Chrome.
• The .PNG image appears identical to VFB when uploaded to Artstation (Chrome).
• The .PNG image appears identical to VFB when viewed in Adobe Bridge full screen preview (spacebar).
• The .PNG image appears identical to VFB when viewed in Image Glass.

So, Photoshop is mediating the appearance of the .PNG at some point, or Windows is failing to communicate color information - or successfully communicating wrong color information - to Photoshop to cause this behavior(?).

I assumed the 'convert to sRGB' option was not checked in the Photoshop Export Preferences, but enabling that option does not change the behavior.


After testing so many permutations of color settings between Windows, Photoshop, etc., it appears that Photoshop is applying my monitor profile to the untagged image, which is causing the color change (darkening / contrasting) on export.

The question is why is it doing this?
Is Windows color settings involved?

[cjwidd]

This seems to be working - I don't entirely understand why...





Import dialog for .EXR - same settings apply for .PNG

[cjwidd]

If anyone has any thoughts about why these settings might make sense or why they are utterly wrong, I'd be very interested to hear them.

[Juraj]

I give up :- )

Your situation is not different to one the previous users asked. On previous page I outlined exact solution. It doesn't feature monitor profile in Windows at all, I highlighted like 5 times in row that option is wrong. It's not "working". You only believe it does, but that was also explained.

So basically a monitor-specific color profile is being applied to the display, e.g. Dell.icm.
The image in the Corona Renderer VFB is modulated by Dell.icm

This is not correct. Corona Rendered is not modulated by anything. Corona and 3dsMax fully ignore your Dell.icm, they are not color managed ("color-profile aware" in other words).

[cjwidd]

Right, as you've said several times before, it's not "working" but it appears to produce a consistent image between applications.

It seems strange because I reviewed images produced this way on other devices - that have not been tampered with in color settings - and the images remained consistent, e.g. Dell laptop, Google Pixel.

[lupaz]

This is correct workflow for this monitor for 3dsMax/Corona.

1) Monitor OSD Menu: Select sRGB mode. Then adjust brightness to your liking. (Fun fact: Calibration is also done to exact brightness levels, but if you move it +/- 50perc. the difference in accuracy is not drastic).
2) Type Color management into taskbar in Windows, select your monitor, check "Use my settings" and select "sRGB" ICC profile. Set "Use as default".
3) When loading any rendering into Photoshop, you don't need to do anything if your settings are set to "Don't Ask". It will stay unmanaged and you only need to "Assign" sRGB profile at the end of export, for examply when saving to final file. Don't convert to any other profile.

The above workflow doesn't work for high-gamut displaying (DCI-P3, HDR workflow,etc..) or printing (AdobeRGB, LAB,etc.). But since 3dsMax & Corona are not color managed (Autodesk Maya and Vray for example are), this is the best scenario to use right now. Least headaches. Colors are always correct, you're just not using wide-gamut capability, which is ok since most devices are sRGB only, even today.

Thanks Juraj. I set it up like this on a new computer and works really nicely.

[Juraj]

There is now (since late 2021) alternative solution because of https://github.com/ledoge/novideo_srgb

it's small tool that superimposes color-profile on non-color managed application. It's not perfect but it's something.

But color-management is still needed on Autodesk & Corona side. I've heard rumor of something next year

[lupaz]

There is now (since late 2021) alternative solution because of https://github.com/ledoge/novideo_srgb

it's small tool that superimposes color-profile on non-color managed application. It's not perfect but it's something.

Thanks. Yes. I saw this on another of your posts, but you mentioned possible conflicts and I rather stay away for now.