Canon F-1N can't focus to infinite. Help please!

Hazebloom · May 27, 2011

Honoured community,

I just registered to this forum which I was lurking since while. Lots of valuable knowledge here. Respect! :thumbup: Now I'd like to hijack a bit of your precious bandwith.

I'm seeking for advices for the F-1N I got yesterday as part of a swap deal. I didn't check the beast in detail as I have 3 month return warranty. At home I found out that the camera can't focus to infinite with any of my FD lenses :grumpy:

. All lenses are fine on my EF body. And all my lenses were fine on my AE1 which went away yesterday. Therefore I tend to exclude the lenses.

This is really the first time I see such a malfunction on a camera. I couldn't find much on the web either. What could that be? Is it a major problem? Can it get fixed? Any hint would be highly appreciated. I'd like to keep this body and get it fixed by the dealer which would not be a problem if only it's technically feasible.

And as we're here: what else shall I check. Does the F-1N has any particular weak points or known issues?

Many thanks in advance.
HB

Hazebloom · May 27, 2011

Therefore I tend to exclude the lenses. ... from suspicion

compur · May 27, 2011

A repair tech would have to look at it to be sure. It could be simple or it could not.
Something simple would be, for example, the focusing screen having been removed
and then re-inserted upside down.

The problem could also be in the prism (assuming you're using one). You might try
removing the prism and seeing if you get a sharp focus at infinity on just the focusing
screen (use a magnifying glass if necessary to see the screen). If focus is OK that
way then the problem is in the prism.

Mitica100 · May 28, 2011

Hazebloom said:
Therefore I tend to exclude the lenses. ... from suspicion

You can try to see if the lenses are at fault. If it has two lenses or more and you can't seem to be able to focus at infinity, then I suspect it's not the lenses.

There is a simple test you can run, you will need a good loupe (magnifier) and some regular, opaque 3M Scotch Tape. Put camera on tripod, open back, stick a piece of Scotch Tape over the film opening, focus at infinity (on the lens) and look at the image formed on the Scotch Tape. It will be upside down and right side left but you will be able to tell if it's out of whack with the aid of the magnifier.

Compur (above) is right about the focusing screen being reversed by some incompetent repairman, you might want to check that.

Also, check if the mirror returns all the way down or if something makes it stick forward a little bit, enough to change apparent focus.

Good luck and keep us posted.

Hazebloom · May 28, 2011

Thanks Compur & Mitica,

Thanks for your helpful advices. Today I brought back the camera (the dealers here are generally easy going for that, it's one of the good things in Korean tradition, but you won't wait too longtime. Always better if they still remember your face ...). So he took the cam to his own repair shop and I got it back few hours later. No more problem. From the explanation I kind of understood it was the mirror. Now I'll check the scotch tape trick to make sure it's not only sharp in the viewfinder but also on the film plane.

Now, it was my lucky day today: he got a 55 1.2 SSC in his shop today and I got it out for what I consider a steal. That fits so nicely to my F1! Then, on the way home I got an car crash. Nothing serious but had to spend 3 hours at the cop shop. Aand I couldn't do any shots there!!!

Again thanks, I'll keep you posted after the scotch test.
Cheers,
HB