(1) I have a Canon F1n w/AE Finder that has been to Canon twice for cleaning, calibration and parts replacement. It has served me quite well until recently, when remounting the AE Finder I noticed that the right-hand-side (manual) exposure scale in the viewfinder is blocked. (I can only see a tiny fraction of the shutter speed indicator at the bottom) The lower (Av) scale works normally when I set the shutter speed dial to 'A'. It appears as though the 'blind' that covers the right-hand-side scale when the shutter speed dial is moved off A is stuck. I suspect (rather, 'hope') that the problem is common or trivial and that the remedy is equally trivial. Has anyone had a similar problem? (2) As a side note, I've been using a Canon FL 58mm f/1.2 for some time before I noticed in the manual that I'm not supposed to be able to mount this lens on the F1n. Could this be the source of my viewfinder problem above? If not, can anyone tell me why I'm not supposed to be able to mount this lens, since it seems to work fine otherwise? (I've only ever shot negative film with it, so I can't vouch for its exposure accuracy.) Thank you in advance for your help and insight.
I have also experienced the problem you refer to in (1). The linkage that connects the blind to the little plunger on the side of the AE head had worn. It's a simple matter to have it fixed. In my case when I went from manual to Aperture-priority mode the blind didn't lift sufficiently to clear the shutter-speed scale. As for (2) I have a feeling that it's the rear extension of the lens that fouls the mirror, but I'd need to check that.
Thanks for your prompt response! I guess it's back to the shop with the body. :| As for the 58 1.2, I'll keep using it, since it doesn't appear to hit the mirror. I remain curious, though, as to the explicit warning in the manual...
Update: the camera went back to Canon Canada; the repair was $185CDN after taxes. While the camera was away, I picked up an FD 50mm f/1.4 on ebay to replace the 58mm. I asked the desk personelle at Canon and emailed Canon HQ about the 58mm, and neither could give me a definitive answer as to why I'm not supposed to be able to use that lens. (I'm doubting that it was the cause for the viewfinder problem.) I'll either sell the 58 or just hang on to it... it makes a great loupe. Thanks again for the help.