preview mode was probably a fairly close representation of time in this image... this mode has bryce ignore areas where there are no objects in the scene..so if you had like a lone boat on the water...itd pay the most attention to the water and the boat (not the sky)... in this image there is no area that is empty...so the time it took to render in fast preview mode is probably somewhere in the area of 80%-85% of the time btw, if you let Bryce actually antialias this then preview mode is pretty much useless because according to the book it will then make a full render (of course a full render from the start is always better in appearance shrug) as for each light squaring render time...ummm ...not sure about that..I do know that one light in a scene may render in 5 seconds and that 2 lights in the same scene does not make it take 25 seconds... its all transparency, bump, complexity of material (like procedural textures increase render time), and a partridge in a pear tree.... :) BT