Folks,

I'm shimming a ground glass in a 8x10 camera back that had a fresnel installed between the ground glass and the lens. The back measures 0.207" and the T-distance of an 8x10 film holder per Alan Brubaker's site is 0.250" with no film. Film that I've measured is 0.007".

So for the image forming surface to be in the same place as the emulsion, the shim would need to be (0.250 - 0.007) - 0.207 = 0.036". This would make the camera back 0.243" thick, which is consistent with another known good 8x10 I have (0.243" - 0.247").

Right?

If anyone has a known good 8x10 back, I'd be curious in what it measures.

Cheers, Steve