Bronica GS-1 Dirt on Mirror

[bob_myers4]

Noticed some dirt (not dust) on the mirror in my GS-1 Bronica. Is that

something I can clean or should I just forget about it? I see lots of

posts about cleaning and they jump from "Don't do anything" to "Yes,

you can use your lens brush." I think the dirt won't come off with

just compressed air (with proper precautions) or a lens brush. Any

suggestions? Anyone dealt with this? Thanks.

[richard baznik]

I'd go as far as the brush myself, but no further -- too much risk of knocking the lens out of line, producing light leaks, etc. If the brush doesn't do it, take it to a technician.

[roland_haid]

Dear Bob, I heard that argument a lot of times. But if you work on a camera (repair or replacement), shure, you will get your mirror dirty. I have cleaned the following mirrors: Rolleiflex (1931), mirror very dirty with a lot of grease, with Ethanol (pure 100%, water free), Hasselblad 2000 FC/M and EL/M (Tetenal optics cleaning fluid). Wipe gently, ofcourse. Mirrors are coated with aluminium rather then silver because that last longer. Remember that in the old days the Daguerre plates (silver coated) were polished after silver (not mercury) coating. And aluminium is even harder. Regards,

[roland_haid]

Ah, I forgot to mention that best position for cleaning a MF mirror is in the *mirror up* position, with the screen removed. The advantage is that you can't de-adjust the mirror because its pressed into its foam bed.