Quote Originally Posted by Murray@uptowngallery
I would like to hear how people implement mounting and light traps for film holders on homebrew cameras.

I am currently making a 5x7 box camera and am using picture frame moulding I happened to have with the right rabbet depth to fit the 5x7 film holder snuggly. Basicly I made a three-sides picture frame that the film-holder slides into (I made ground glass same size with spacers glued on the glass). I haven't figured out yet what to do about the 4th side regarding light traps. What is the aluminum wedge for on film holders (wooden ones)? I'm guessing with a spring-pressure method it pops into a groove on a standard camera back, perhaps for registration (uniformity of isertion distance actually).



You are correct that the rib lock on a film holder seats into a corresponding groove on the camera back. This provides the light trap for that side. The other three sides are light tight by the 90 degree bend that the light would need to navigate in order to enter.