short question about lightsetup for caustics

[quirin]

the way vray produces caustics is a little bit confusing for me!

just tested a scene with a directional light - beautiful caustics, and
a spot light with the same settings - no caustics at all?

is there probably a difference how vray emits the photons for
directional and spotlights?

[freak]

spot lights' light is spread out....direct lights r not..when u do photons...its best to use directl lights.....at least that's what i always do....