I have a Hutech modded 40D and am trying to build a light box for the taking of Flats. I believe the Flats have to be at half-well capacity to give proper results but I can't find what value to look for (and even where to find it).
Any help would be appreciated.
When I take flats with my 20Da, I use the histogram as a guide instead of well capacity calculations.
I try to have the spike at around 1/3rd the way along the histogram.
Yep, approximately a third from the left (on the camera's LCD) .
I'll see if I can dig up an old one when I get the chance and post what my histogram looks like in Photoshop for you.
That's great. My first attempts (before this thread) were way too bright. Now I have to work on getting a uniform brightness across the light box. Many thanks.