I really only know enough to be dangerous Mark, but here's what a typical single flat frame looks like for me and my light box. I mucked up wiring in a step down resistor and LED layout the Jarcar guy so nicely sketched out for me, so now just run it off a number of 12v bulbs - thus the yellow/orange cast. Box made up from white card as described by Barry from ASIGN observatory.
They end up as monochrome masters of course and seem to work fine. This was taken by the 450D through the 8" Newt.
Was yours through an ED80? Doesn't seem to show any vignetting out at the corners?
