chromatic aberration with VRay

[piotrus3333]

some early tests with rendered chromatic aberration effect.

ps: yes, I know it's easier in post so no need to remind me that - but it's still a hobby every now and then so consider it a fun project or a bit of r&d at best, thx.

[^Lele^]

very nice, how did you go about it?

[piotrus3333]

basic principle is nothing new - just rendering through dispersive lens (2.0 in vray calendar). very inefficient (rendertimes x12 on simple scene) and depending on the shape of lens creates some issues with dof. also not very castomisable, basically just strength of the fringe and shape of used lens.
I tried to make it somewhat more usable (extremely niche gimmick but still). got some ideas from vray 1.5 times (true cgi archaeology..) - now renders without dof are roughly 50-75% longer and when you consider time spent rendering dof with all the bells and whistles - I would say you could live with that.

and you can fully control colors - cyan/magenta on attached crop.

I would still call it work in progress but if anybody is interested in such "no post" approach I will try to post some more.

[^Lele^]

I was thinking of a VRLens file, is that what you mean by "rendering through dispersive lens (2.0 in vray calendar)" ?
Or you mean literally putting a geo in front of the camera?

[vlado]

Looks good! One of our interns also did an experiment with raytracing a real camera system; some results are below. We still haven't decided if we want to put this into V-Ray officially or just dump it on Github.

Best regards,
Vlado

[^Lele^]

I vote for inclusion. ^^

[piotrus3333]

Geometry in front of vray camera - I thought VRLens file would produce just distortion and not color aberration. but because of rendertimes I simplified it to rendering through single plane (one poligon) but than I encountered a bug in RT (contacted support about that, reference number is 114-046-024 i guess, all the details are there).
so my current "lens" only works in Adv right now.

nice experiments, ones with aspheric elements are the best. I stopped at one lens hence problem with dof - everything at least a bit off focus. and kudos to the intern.

how would that look implemented into VRay? helper like stereo rig? connected to modeled lens system??

and I still need to do comparison with some post tools for chromatic aberration to look for advantages of doing it in render (besides it being a cool trick)

[^Lele^]

This



had this come to mind instantly.

https://www.youtube.com/watch?v=oxHnRfhDmrk

[Morne]

I vote for inclusion. ^^

+1 on that Lele

[werticus]

Would be cool if we could get a lens effect for CA.

[bardo]

+1 on that Lele

Me too! It's interesting to see

[Buck]

Looks good! One of our interns also did an experiment with raytracing a real camera system; some results are below. We still haven't decided if we want to put this into V-Ray officially or just dump it on Github.

Best regards,
Vlado

Those are fantastic! Especially the ones where you can feel the curvature of the lens as the sides swirl. I was obsessed with this effect in certain large format lenses when I was into film photography, lots of "petzval" type lenses have this effect. I still have those lenses in hopes of someday building a digital large format camera

I've experimented with ways of simulating this in Nuke, have found a few decent solutions, but nothing really note worthy. I'd love to get ahold of what you have to recreate them!

Some odd experiments with some large format cameras and lenses made from various things, raw lens elements, telescope parts, and what not:

[piotrus3333]

comparison with ArionFX for ps:

[piotrus3333]

rotated domelight - notice how fringe changes with background (hair):

edit: open images in separate tabs in browser to compare easily.

[stevesideas]

Any news on this ? Would be great to see this included in Vray