Cannot focus properly with Yashica FX-3, loose mirror?

Discussion in 'Camera Building, Repairs & Modification' started by ColdEye, Jun 15, 2011.

  1. ColdEye

    ColdEye Member

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    Hi, I am experiencing a problem with my FX-3 Super 2000. I cannot seem to get stuff in focus, especially at large apertures (1.4-4). My subject is always out of focus. I am very sure this is not user error, or slow shutter speeds that cause it not to be sharp. The minimum shutter speed i use 125. I've read in another forum that these cameras tend to have their mirror become loose, how do I fix this?
     
  2. Diapositivo

    Diapositivo Subscriber

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    Has your camera a loose mirror, though? (if it is, you should see it by just taking the lens away and taking some shots without film, just to see what the mirror does).

    I would make some test shots with film focusing at infinite with a normal lens. If the actual picture is in focus and the viewfinder image is not, that means something in the viewfinder is out of specifications (mirror, focusing glass). If the actual picture is not in focus (and it should be regardless of how the image appears in the viewfinder, as you focused at infinite) that means the problem is somewhere else (film pressure plate?) because the mirror, or the viewfinder in general, has no effect on the focus of the final image.

    For the test to be reliable, tripod and flexible cable (or self-timer) are mandatory. If your camera doesn't have mirror lock-up, you should use shutter times shorter than 1/60 (or longer than 1 second).

    If this test shows a picture not well in focus, then you probably have a problem with the film pressure plate. If the test shows a picture in focus, and the image in the viewfinder not in focus, then you have a problem with the viewfinder (not necessarily the mirror).
     
  3. ColdEye

    ColdEye Member

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    I see. In one of the pictures i took, I remember clearly that it was taken at around f8 and in the viewfinder, the picture is in focus. But when the scans came it was just slightly in focus. It is saddening because I took almost 12 rolls with it before I had the films developed. Bad practice I guess. :tongue:
     
  4. Diapositivo

    Diapositivo Subscriber

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    Just for added clarity, I'd suggest you should to examine in those 12 rolls the pictures which were taken with the focus certainly set at infinite (and the subject at infinite as well :smile: ), better if wide open. If those are in focus, it's the viewfinder's "registering" which is out of specification.

    For any image which was taken let's say at 5 metres, and which is not perfectly in focus, you cannot know whether the problem is in the viewfinder (which shows focus a bit behind, or before, the lens plane of focus) or in the film pressure plate (which doesn't keep the film on the intended camera focal plane).
     
  5. BrianL

    BrianL Member

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    One thought also, do you need a diopter on the viewfinder. You may want to have your eyes checked. If so, you may be focusing to where in the viewfinder the subject is focused but the result is out of focus. I find different cameras seem to need the accessory more than others. My dslr needs the adjustment for me to use while the Bronica does not. One way to check is to focus the subject to the sharpest point using the microprisms and then see if the split image method coincides. I have 2 FX-3s and neither exhibit your problem but, I've not run a roll of film through them in years. For the cost of a used body, it is probably not worth fixing it if it needs repair. I do like the body as mine have gone through hades and back and one only had to have the covering redone (homebrew years ago) and the other has a bit of a stiff winder.