Chromatic aberration before glare or afterwards?

[Ihno]

This is a compositing question.
Whats the right order?
In real world photos, is CA on the glare or is the glare on top?
And if the first is right: Should I make the glare respect the CA? Or should I generate it from the raw image and add it to the CA'ed image?

[vlado]

Good question; let me ask Asen and see if he has any thoughts.

Best regards,
Vlado

[vlado]

Here is the answer I got:

I think first chromatic aberration, because the light first passes through the lens (which causes CA) and then through the aperture (which causes most of the lens glare).

However because we don't have chromatic aberration built-in, there is no easy way to do that; you'll have to save the raw image, apply the CA, then load it back in the VFB to apply the glare. I guess this is where having built-in CA would be useful.

It would be interesting to actually make an experiment and see if there is a huge difference if you apply CA first and then the glare on top of it, or vice versa.

Best regards,
Vlado

[Ihno]

Here is the answer I got:

However, because we don't have chromatic aberration built-in, there is no easy way to do that; you'll have to save the raw image, apply the CA, then load it back in the VFB to apply the glare. I guess this is where having built-in CA would be useful.

Best regards,
Vlado

Thank you!
Right now I'm taking the output from fusion into max and use it as an environment in screen mode. That works quite well and I can render it through backburner.

It's good to know, even when I don't have the time for the extra pass and use fusion's clunky tools for generating glare!
If we'd only could get the vray lens effects along with the denoiser into fusion. But they don't have a sdk if I remember correctly.

It would be interesting to actually make an experiment and see if there is a huge difference if you apply CA first and then the glare on top of it, or vice versa.

I think it might change the color of the glare a bit.
I'll see if I can find a scene which I can show to test it.

[Ihno]

First a quick test under laboratory conditions.

All have the same settings for glare (default but 2 for intensity)


Vray glare without CA:


With CA before glare:

Vray glare with CA Type 1:



Vray glare with CA Type 2 in very aggressive settings:



Vray glare with CA Type 2 in modest settings (as I use it most of the times.):




If anyone is interested:
The CA Type 1 is from https://gumroad.com/l/NJTC
The CA Type 2 is from the MT Glitch package which is free and available through reactor https://www.steakunderwater.com/wesu...amp;amp;t=1775.

[Ihno]

With glare before CA:

Vray glare with CA Type 1:



Vray glare with CA Type 2 aggressive:



Vray glare with CA Type 2 modest:




To me the CA-before-glare Images are looking way more realistic.
I'll test it in a production scene later, the difference will be less obvious I think.