Canon F-1N: No infinity focus

Discussion in '35mm Cameras and Accessories' started by Tony-S, Sep 15, 2013.

  1. Tony-S

    Tony-S Member

    Messages:
    786
    Joined:
    Aug 16, 2009
    Location:
    Fort Collins
    Shooter:
    Multi Format
    I just received an EX grade Canon F-1N from KEH and it does not focus to infinity. I have reseated the focusing screen (PE, split-image/microprism) and the problem persists. For example, when my 24mm f/2 is set to infinity, it focuses at about 10 feet. With my 50mm f/1.4 the problem isn't as bad, but it, too, is not reaching infinity. Both lenses work fine on my A-1. Any ideas? I hate to return it but will if I need to. A bit frustrated with KEH recently - I had to send two copies of the 35-105 f/3.5 back because of different problems.
     
  2. frobozz

    frobozz Subscriber

    Messages:
    1,361
    Joined:
    Feb 19, 2010
    Location:
    Mundelein, I
    Shooter:
    35mm
    That's downright bizarre. I'm not even sure I can figure out how that can happen?! Assuming the screen and prism are installed properly... Is the mirror not returning all the way down? (I still don't think that would cause this.) Any evidence that the lens mount has been messed with?

    Duncan
     
  3. Markster

    Markster Member

    Messages:
    307
    Joined:
    Dec 30, 2010
    Location:
    Denver area
    Shooter:
    35mm
    It has to either be the prism in the viewfinder not being seated properly, or possibly a major problem with the mounting bracket for the lens itself.

    I don't see how the problem wouldn't be rather obvious, though. If it were a mount problem you'd be able to see some issue before putting the lense on, and the viewfinder only fits on one way if I recall.

    It's rather strange.
     
  4. momus

    momus Member

    Messages:
    2,706
    Joined:
    Jun 14, 2009
    Location:
    Lower Earth
    Shooter:
    Medium Format
    I'm not sure how your camera is set up, but I have a F-1, 2nd version, and it's possible to put the prism housing on wrong and not have it fully seated. I would make sure it's all the way down on the camera. If that isn't the problem, and you see nothing wrong w/ the mirror/lens mount, I would send it back. I buy from KEH a lot, and usually have good luck, but they aren't perfect. The good thing is that they will take a return. Aren't their cameras warrantied for 6 months? You could always send it back to them to be repaired.
     
  5. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

    Messages:
    18,000
    Joined:
    Sep 7, 2002
    Location:
    Honolulu, Ha
    Shooter:
    Large Format
    If you have the New F-1 (sometimes called the "F-1N" not to be confused with the second version, the "F-1n") then it sounds like you may have the focusing screen upside down. I didn't know that it was possible to install it upside down, and I'm not about to try it on mine, but the matte/grooved side should be down with the black edge under the tab at the front of the camera and the chrome edge on top toward the back of the camera.

    If that's not it, it's something like a mirror alignment problem. Make sure there's nothing obviously preventing the mirror to return to the normal viewing position.
     
  6. Yeeski

    Yeeski Member

    Messages:
    47
    Joined:
    Aug 26, 2006
    Shooter:
    35mm
    It has to be either (a) the focusing screen is defective or isn't properly installed, or (b) the mirror is out of adjustment. It can't be the fault of the viewfinder since it only re-orients the image from the focusing screen. With a basic (i.e., non-magnifying) waist level finder, you are essentially removing the prism viewfinder and focusing directly off the focusing screen. The waist level finder is nothing more than a hood to block stray light. Check to see if your mirror is all the way down and seated.
     
  7. ic-racer

    ic-racer Member

    Messages:
    7,513
    Joined:
    Feb 25, 2007
    Location:
    Midwest USA
    Shooter:
    Multi Format
    This:
    f1mirroradjust.jpg
     
  8. John Koehrer

    John Koehrer Subscriber

    Messages:
    6,463
    Joined:
    Apr 3, 2004
    Location:
    Montgomery,
    Shooter:
    Multi Format
    Ever seen a broken body casting? It was held together by the top & bottom covers.
     
  9. clayne

    clayne Member

    Messages:
    2,805
    Joined:
    Sep 4, 2008
    Location:
    San Francisc
    Shooter:
    Multi Format
    Seems pretty unlikely with an F-1!
     
  10. Andrew K

    Andrew K Subscriber

    Messages:
    570
    Joined:
    Mar 17, 2010
    Location:
    Melbourne, A
    Shooter:
    Multi Format
    Try this - if it doesn't work then the spring on the inside of the mirror box is broken (it's happened to one of mine).

    Sorry to say it's a MASSIVE job and not worth doing, but you can file the stop down to adjust infinity focus (again what had to be done to mine).

    Its a job I wouldn't tackle, and I used to fix then when I was a camera tech at Canon in the 90's!
     
  11. Charles Wass

    Charles Wass Subscriber

    Messages:
    62
    Joined:
    Aug 26, 2013
    Location:
    Barcelona/Có
    Shooter:
    Multi Format
    If the mirror is seriously misaligned I would expect that the viewfinder image would show some vignetting at top or bottom, though I believe the viewfinder coverage is not 100%. If the camera is the F-1n (not New F-1, AKA F-1N) then the meter will not work with the screen upside down. I have looked at both cameras and it seems it might be possible to install the screen upside down.
     
  12. Tony-S

    Tony-S Member

    Messages:
    786
    Joined:
    Aug 16, 2009
    Location:
    Fort Collins
    Shooter:
    Multi Format
    The focusing screen is in correctly and mirror is returning, so it must be an alignment issue. Time to send it back to KEH for a replacement. I really wonder how much QC testing KEH does. I've been using them for years and until recently have not had problems.

    Thanks to all - I appreciate your guidance.
     
  13. Tony-S

    Tony-S Member

    Messages:
    786
    Joined:
    Aug 16, 2009
    Location:
    Fort Collins
    Shooter:
    Multi Format
    Well, the replacement camera arrived today and seems to be in good working condition. However, one of the screw-in bottom covers is missing. I have an email to KEH requesting they send me a cover, but I'll report back here if for nothing else but to show how KEH responds.
     
  14. elekm

    elekm Member

    Messages:
    2,056
    Joined:
    Sep 12, 2004
    Location:
    New Jersey (
    Shooter:
    35mm RF
    The angle of the mirror has to be out only a fraction of a millimeter for a camera to not focus correctly at infinity. And some cameras are easier than others in making this adjustment.

    I had the same problem with a Yashica Contax 139 Quartz. On that camera, you have to remove the front body panel and turn a small screw to adjust the angle of the mirror.

    On a Zeiss Ikon Contaflex I (and other cameras), you remove a cap on the base of the mirror box and turn a small post.
     
  15. Tony-S

    Tony-S Member

    Messages:
    786
    Joined:
    Aug 16, 2009
    Location:
    Fort Collins
    Shooter:
    Multi Format
    In case you missed it, I returned the defective camera for a replacement. It seems to work perfectly fine. It's just missing one of the bottom covers.
     
  16. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

    Messages:
    18,000
    Joined:
    Sep 7, 2002
    Location:
    Honolulu, Ha
    Shooter:
    Large Format
    If you search on eBay, you can usually find sets of the three bottom caps at a not unreasonable price.
     
  17. dynachrome

    dynachrome Member

    Messages:
    1,012
    Joined:
    Sep 16, 2006
    Shooter:
    35mm
    I have a Nikon F2 body which will not allow correct infinity focusing. For now I'm not doing anything with it because I have other F2s. Eventually I might send it to Sover Wong. If he can't fix it, I don't know who could.
     
  18. Jon Goodman

    Jon Goodman Member

    Messages:
    656
    Joined:
    Jul 22, 2005
    Location:
    Dallas, TX
    Shooter:
    35mm
    Mike Elek is correct in telling you that only a small difference in mirror adjustment will wreck the focusing ability of a camera. If you know your focus screen is installed correctly (not upside down or cocked in the frame), then I'd look at the focus screen first.
    Jon