My biggest confusion at the beginning of the radius puzzle was that when you increase the radius, all things out of focus get blurred. I misinterpreted lens radius to be the radius from the arc the lens made to the centre of that arc. Logically the bigger the radius, the smoother (? is that the right expression ?) the curve of the lens the less out-of-focus blur. Seems it doent work that way :-), I now interpret the radius to be the thickness of the lens. I don't know if that is correct but it works for me. cobalt: I usually think along those lines as well, its just in the render i was trying o make I wanted to look like i was shooting a landscape from great hight (like 4000-5000 feet, just before the skydiver has to pull his pilotchute) so in that case the movieset gets a little huge and goes off-budget ;-). Cheers, Zigster.