I use Bryce 5, and yes, Bryce 5 does have caustics, though I use them sparingly. Eats up much render time (Bryce ain't known for its fast rendering you know!). I have ordered CS2 and so I should have my hands on it in about 10 days. I have been fighting with Ray Dream Studio 5.5 until now and have grown tired of its bugs. Alduin