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Mamiya 645 to m4/3 adapter?

Discussion in 'Adapted Lenses' started by snegron, Jun 5, 2013.

  1. snegron

    snegron Mu-43 Regular

    166
    May 9, 2013
    SW Florida
    Just curious to know if there are any Mamiya 645 lens to m4/3 body adapters on the market?
     
  2. carpandean

    carpandean Mu-43 Top Veteran

    827
    Oct 29, 2010
    Western NY
    I don't know if there is a direct one, but if you already have an adapter from some DSLR mount to :43:, then you could always just buy a 645 to the same DSLR mount adapter. Those seem to be more readily available.
     
  3. snegron

    snegron Mu-43 Regular

    166
    May 9, 2013
    SW Florida
    True. I wonder if there would be a noticeable loss of IQ though (like when you add several teleconverters)?
     
  4. entropicremnants

    entropicremnants Mu-43 All-Pro

    Jul 16, 2012
    John Griggs
    That's a heck of a crop factor boost. about 1.6 vs 35mm which is 2 vs mft. So about 3.2x factor. The equivalent area is the square of the crop factor so the mft sensor is about 1/10th the area of the 645 medium format film. I'll show why that's significant later. These are round numbers but sufficient to make a point.

    A "standard" Mamiya 645 80mm lens would be a 256mm equivalent lens. Wow. Don't even THINK about trying to get anything wide enough in medium format to be less than a telephoto on the mft camera.

    And I do think the IQ could be disappointing. Let's say you have a 16 megapixel mft sensor. You'd have to put 10 of them together to make the area of a 645 film image. If you'd have to have about a 160 megapixel sensor in the 645 to have the same "pixel pitch" more or less.

    You'd need one heck of a sharp lens to satisfy that sensors IQ. I suspect the 645 might be disappointing on an mft camera.

    Somebody can run more exact numbers if they want -- but that's a good approximation and tells you want you will be running into.
     
  5. ptolemyx

    ptolemyx Mu-43 Veteran

    290
    Jun 19, 2012
    Vancouver, BC
    Ben
    entropicremnants: That's not right. All lenses of a given focal length (whether 645, full-frame, micro four thirds or CCTV) will have the same FOV on a given sensor size--an 80mm Mamiya lens adapted to MFT will have a FOV comparable to the Olympus 75mm.

    Sharpness will probably be a bit disappointing, but when you consider that 645 is for making big prints, it's probably not going to be as bad as you suggest.


    (EDIT: I might have misunderstood what you meant by "a 256mm equivalent lens"... these equivalence discussions get pretty hairy. Apologies if so. :)
     
  6. entropicremnants

    entropicremnants Mu-43 All-Pro

    Jul 16, 2012
    John Griggs
    Ha ha, you did misunderstand but the confusion is because the area of the sensor intersects only a small area of the projection generated by the FOV angle you cite. So, no of course the lens doesn't change but the effective FOV does.

    I had a 645 (two actually) and the 80mm 645 lens has the same FOV on a 645 as a full frame Nikon 50mm does on a Nikon -- so that part of your statement was incorrect.

    One a fullframe Nikon the 645 80mm lens has the equivalent FOV of a 130mm Nikon.

    Just the way it works.
     
  7. Crdome

    Crdome Mu-43 Hall of Famer

    Sep 11, 2011
    West Central Indiana
    Chrome
    Ben -I think you are confusing FL and FOV. Crop factor is the ratio of the cast image circle to the sensor size.

    Yes, it can be done, but at what cost? Hanging a 654 or 6x6 lens on a Micro 4/3 defeats the purpose. The lens is huge. My 6x6, 85/2.8's has a diameter equal to the height of my MFT body. Sticking it on with two adapters will produce a horribly unbalanced front heavy combo.

     
  8. carpandean

    carpandean Mu-43 Top Veteran

    827
    Oct 29, 2010
    Western NY
    Since the flange back distances are ...

    645 >> most DSLRs >> :43:

    neither adapter would require any glass. As such, other than slight differences in total length (depending on the quality of the two adapters), likely affecting the ability to focus to (or allowing beyond) infinity, and maybe some loss of rigidity would be the only significant differences between the stack and a single adapter.
     
  9. ptolemyx

    ptolemyx Mu-43 Veteran

    290
    Jun 19, 2012
    Vancouver, BC
    Ben
    Which part was incorrect? I was responding to your "256mm equivalent" statement .. it's true that an 80mm lens on MFT has an FOV equivalent to a 256mm lens mounted on a 645, but that's not really relevant to the OP's question, so I wasn't sure what you were getting at; 80mm is perfectly usable on MFT!

    Er, you've lost me again. An 80mm lens mounted on a fullframe Nikon will have the same FOV whether that 80mm lens projects a 645-size image circle or a FF-size image circle.

    Did you mean to say that an 80mm 645 lens mounted on a FF camera has the same FOV as a 130mm 645 lens mounted on a 645? :confused:
     
  10. snegron

    snegron Mu-43 Regular

    166
    May 9, 2013
    SW Florida
    On a side note, I find it amazing how technology today has changed everything. With medium format you would get better IQ mostly because of the larger film. Top grade glass was desired but not critical to obtaining a good image; you could get away with average lenses and still get better images than with 35mm film. Today FX sensors require better optics in order to produce better IQ images. Mount a sub-par lens onto an FX camera and you will see the optical defects! :smile: