Should I paint the clamp on my focusing screen mount?

[Forest_rain]

I know this is probably a small question, but I cleaned my focusing screen by soaking it, but I managed to take the black paint of the mount.


It seems like they painted it in order to flock light reflections...they also used black tape to seal the focusing screen onto the prism.


I've been using one coat of primer plus two coats of paint, but I'm worried with this somewhat thick coat it will cause space between the mount and the camera body. Is this an issue for focusing?


This focusing is actually quite thick and seems to have a "lens-like" magnifying quality, so I'm worried that it will cause the focus to misalign with the film plane.


Should I just not worry about painting the clamps? It seems like the mirror would block any reflected light anyway, maybe.

 

[monopix]

If you add or remove anything from the surfaces that affect the screen position then the focus will change. But the camera will probably have a focus adjustment so you could readjust it.

 

[Forest_rain]

If you add or remove anything from the surfaces that affect the screen position then the focus will change. But the camera will probably have a focus adjustment so you could readjust it.

I decided not to paint the part where the screen clamps to make sure it's perfectly flat. Also it seems more difficult to add space than to remove it.


The best way to adjust focus would be just to adjust the screws on the focusing screen or add paper shims between the screen clamp and camera body correct?


Focus to infinity, tape scotch tape to film plane, use loupe on film plane. Does that sound right?

 

[monopix]

The best way to adjust focus would be just to adjust the screws on the focusing screen or add paper shims between the screen clamp and camera body correct?

Depends on the camera. Adding shims might work but if there are screws then better. Sometimes there's a screw that adjusts the mirror position to get the same affect. What camera is it?

Focus to infinity, tape scotch tape to film plane, use loupe on film plane. Does that sound right?

That usually works.

 

[Forest_rain]

Depends on the camera. Adding shims might work but if there are screws then better. Sometimes there's a screw that adjusts the mirror position to get the same affect. What camera is it?


That usually works.

It's a Retina Reflex S. Interesting but extremely infuriating camera, very complicated.


There are screw threads with "ends" on them as you can see circled in this picture. I'm thinking these might be able to shimmy up the focusing screen for adjustment if I adjust the screws once the screen is mounted.

 

[monopix]

Looks like it. I know nothing about Retinas though. I'm sure someone else here must have experience.

 

[Forest_rain]

Looks like it. I know nothing about Retinas though. I'm sure someone else here must have experience.

Looks like those holes are just retainers for screws that don't affect the lift off distance, so that's not it.


Anyway, I attached the screen, reassembled, and the viewfinder focused to infinity OK. Split image was OK at infinity set the the mark on the lens.


Tested the film plane with a piece of tape and magnifying glass. The focus on an object about 15 feet away was "more or less ok". Very difficult because even on a tripod, you need to press the shutter and also need to cock the shutter to see through the viewfinder which moves the camera.


Also, it was very difficult to see without a ground glass and loupe, but it seemed "about the same focus" on the tape.


I'm probably splitting hairs about a thin layer of paint affecting the focus and lift off distance of the focusing screen.


Anyway, if anyone knows how to adjust the focusing screen focus besides adjusting the film plane distance to lens mount, please let me know (for future reference).