Originally Posted by knightly
Nicely done... it's shocking how quickly 1600w of light falls off isn't it?
It sure is, but fall off has, physically speaking, nothing to do with Watts, but with distance between source, subject and backgound
(Twice the distance = loosing 75% of the light.
My Math-English isn't really good but there is an inverted square relation between distance and fall off.
If the source-subject distance (=Ds) is 1 meter and source-backgroud (Dbg) is 4 meter, the background gets 1/(4^2) (that's 1/16th) of the amount of light the subjects gets.
With Ds=2 and Dbg=4 the subject still gets 1/(2^2) (=1/4th of the light).
With a Ds closer to Dbg (like 10 vs 12) the fall off between subject and background is much less. (But you'll need far more power to begin with, because the most of the fall off happens before the light hit the subject in this case.)
BTW, it looks really good.
Fall off doesn't bother me at all.
(When you compare it with a rebel or C300: show some rolling shutter stuff as well