Quote Originally Posted by Photog82 View Post
Sean, will the rectangular grid produce a circular lighted background like the first example?
Yes. It's the size and shape of the cellular parts of the grid that matter most, I think. Check out this comparison (click for larger view).

Attachment 2382

As you can see, the 1/8" sized grid produces a smaller spotlight while the 1/4" grid produces a larger spotlight. The distance from the flash and the wall (and the wall to the camera) remained constant between these two tests. The only thing that changed was that I rotated the flash very slightly to better center the 1/8" test result. Otherwise, everything is exactly the same between the two aside from the different grids.