>>> This is definitely an artifact.>> Am I seeing the spiral pattern that the photons are shot in? I thought that> might be the case, but dismissed the idea...>>
It's indeed the spiral pattern in whitch the photons are shot that you
see here.
Solutions:
Reduce spacing (suggestion: actual spacing/4 or 5) OR increase count
(suggestion: actual count *16 to *25).
Add some jitter to your photons to hide the regularity of the spiral.
Alain
