I have a f/14 90mm BERTHIOT PARIS PERIGRAPHIE No 2 SERIE VI. Gem of a little optic. Stops down to f/56. It throws a beautiful circular image on 11x14 film. Tried to figure out how to use it on my 11x14 Chamonix but would need to fabricate a 90mm recessed lens board to achieve close to infinity focus. Lens has no shutter but could easily be mounted inside one of Polaroid's (MP-4) copal shutters which I already have. Problem with the 90 mm recessed lens board is that access to the shutter's controls is severely hampered. Have seen several different pinhole cameras that have ultra simple backs (-GG) that hold the film holders.

Anyone know of the existence of simple directions to make one of these backs?

The 90mm PERIGRAPHIE would be mounted at its hyper focal distance and used at f/56. Negatives contact printed so diffraction not a factor.