Phwoarrr! Look at the caustics on that!

[phile_forum]

Just trying the caustics in OB4. An oldie, but a goodie. Yes, I turned up the multiplier on the caustics too high but what is bothering me slightly is that little dark square patch in the middle of the ring. It's easy to get rid of in post, but I wonder why it's there at all. It appears whether or not I have caustics switched on. The scene is lit by two luminous polys (210%) and nothing else.

Phil

[except]

I think it's borg excrement.

No idea