Mamiya 645E – Focus Screen Cleaning

My Mamiya has disturbing dust between the focus screen and the magnifier glass, so I decided to do a Mamiya 645E – Focus Screen Cleaning. Even if the dust is not affecting image quaility at all and could be ignored, it disturbes me just looking at it, a personal weakness I would say.

First I tried to blow the dust out, but this is hardly possible, and maybe got worse. Knowing that the Mamiya 645E is not a professional camera, where the focus screen is easily accessable and exchangable, I started to search the internet for a repair manual or blog showing how to clean the camera and the focus screen… but I had no luck at all.

As I have some experience with repair of cameras and lenses, I decided to disassemble the camera of my own, and in the end I succeeded to clean it myself with very good result. But, I must say, that the Mamiya 645E is not nearly designed to disassemble for cleaning of the focus screen. There are challanges.

First of all the focus screen is mounted with springs and is therfore adjustable in distance to mirror, lens and magnifier. When reassemble the focusscreen, it must be correctly aligned again. Missing special optics for that, I did this with the camera partly disassembled, a 50mm lens at f 4.0 by manual measuring the distance to different objects. Not an easy task to do, and I guess I will never know, if it is 100% correctly aligned as it was before.

Secondly the exposure LED was not simple to correctly mount again in order to show the exposure figures in the viewfinder. I adjusted the LED group selveral times over and over again. So there are these challanges and it took a while for me until I was ok with the result.

In the following I documented the steps I did for dissassembly with pictures. It is possible to click the pictures to see my comments. Even if it is selfexplainatory, I want to state that is not a professional repair manual, if you decide to do a dissassembly, it is on your own risk.