Diopter for Contax 645

Discussion in 'Medium Format Cameras and Accessories' started by mthull, Nov 29, 2007.

  1. mthull

    mthull Member

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    Hello,
    I have a Contax 645 and am in need of diopter correction (more than what is built in to the camera). According to the manual the FM(+2) would be the one for me. I have searched high and low on the internet and can't find any reference to this accessory outside of the manual.

    Does anyone out there know where I might find one? (I've checked all of the usual sources, eBay, KEH, etc. -- no luck so far).

    Maybe a custom eyepiece would be an option -- as the normal one is removable. Anyone have experience doing something like that? Or a resource? (I can't wear contacts by the way, which would otherwise be an obvious solution.)

    Thanks!
    Mary
     
  2. Pete H

    Pete H Member

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  3. mthull

    mthull Member

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    Thanks. Unfortunately I think that is for the waist level finder, which I don't use. As far as I can tell -- digging deeply into google, the FM+2 diopter for the 645 is the same as on the RTSIII. So if anyone knows where I can get one of THOSE, that would be it.

    But thanks for the reply. Yes, I would even take a +1 at this point -- but I have a bad feeling there might not be any left in the world.
     
  4. john_s

    john_s Subscriber

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    It's a lot harder these days to get opticians or their suppliers to do this kind of work. I suppose it's because they are using sophisticated machines to do standard jobs (and which can be operated by less trained operators).

    However, it's possible.

    First you need to ascertain the actual diopter you need. I don't know your camera, so bear with me. On some cameras, the eyesight correcting diopter is added to the existing viewfinder (e.g. Leica rangefinders). In other words, nothing is removed before the corrector is attached.

    With other cameras, the eyesight correcting diopter replaces a standard eyepiece. The standard eyepiece might be optically neutral (diopter=0) or it (the standard eyepiece) might have a value which is necessary for a person with normal good eyesight to view correctly (e.g. diopter=-1.5 for a person with normal eyesight). In this latter case, the value printed on the eyesight correcting diopter might be the amount by which it differs from the standard value, not its true diopter as a stand alone piece of glass (or plastic). See http://www.tamron.com/bronica/prod/sq_eye.asp for an example of a standard eyepiece being different to a zero diopter.

    There are standard diopters in glass and plastic available to the optical trades. All you need to do is find someone to cut one down to size and fit it into the frame of your current eyepiece. In addition to opticians, the people who do work for amateur astronomers are worth a try.

    Is there a possibility that the diopter you need has the same mount as another make of camera? Try posting to the medium format forum on photo.net. Someone might have some inside information.
     
  5. mthull

    mthull Member

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    Thanks much -- that is definitely worth a try. And yes, it is the same as on another camera so will post elsewhere on that. Thanks again.