Back Focus Listings for 2 1/4 cameras ?

[CameraQuest]

anyone know of listing for the back focus of various 2 1/4 cameras?

ie the distance between the lens and the film plane?

useful for determining what lenses can be adapted to what cameras,
among other things

Thanks,
Stephen

 

[Beemermark]

https://en.wikipedia.org/wiki/Flange_focal_distance

 

[Godfrey]

Another good resource:
https://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html

One that I found nearly impossible to find anywhere so I measured it myself is the Mamiya Press 23 (Super, Universal, etc) : 61mm.

G

 

[CameraQuest]

Thanks guys,
very useful

Stephen

 

[charjohncarter]

Even with knowing the register I find it really hard to measure that distance on the camera, maybe some one here has a good method.

 

[Godfrey]

Even with knowing the register I find it really hard to measure that distance on the camera, maybe some one here has a good method.

It depends somewhat on the camera, you need to have a clear vertical drop from the flange to the film plane. I use a dial readout caliper with the base sitting on the flange rim and the depth measuring tail reaching down into the camera body. If I don't have that clear shot from the flange itself, I have a little bar of flat, 4mm thick glass that I lay across the lens mount flange that I can use as the base reference for the measurement, and use the same dial readout caliper from that.

A piece of glass up against the film rails provides the focal plane reference point to measure to. Or the pressure plate, if you know how far behind the film plane the pressure plate is supposed to be (usually .001-.003 inch).

G

 

[CameraQuest]

anyone know the back focus for a Norita 2 1/4 ?

 

[Moto-Uno]

Is there a chance it would be the same as a Pentacon Six ?

Which I can measure if it is . Peter

 

[CameraQuest]

Is there a chance it would be the same as a Pentacon Six ?

Which I can measure if it is . Peter

Thanks,
I don't think they are the same