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  1. #1
    dpurdy's Avatar
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    coverage of Leitz M lenses

    I have just discovered that I can get an adapter for my Pentax 67 to make it take M series lenses. That is a very intriguing idea and I wonder if I would get a full circle of image on the 120 film or just what I would get. Anyone ever checked out the circle of light from an M series lens to see how large it is?

    Thanks
    Dennis

  2. #2
    Ian Grant's Avatar
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    Well as the register of the two lens mounts to film plane is very different that's going to impose huge restrictions, certainly no Infinity focus, except some of the M series lenses split & the lens part (minus focus helical) could be fitted in bellows. Any adapter is probably for Leitz macro lenses, and at one time they did make lenses that covered larger formats.

    Ian

  3. #3
    Lee L's Avatar
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    Quote Originally Posted by Ian Grant View Post
    Well as the register of the two lens mounts to film plane is very different ...

    Ian
    27.95 mm for M-mount, and I believe 85 mm for the Pentax 67. As the lenses will be pushed so far out, they'll have greater than the infinity designed coverage, but I'm sure it will greatly vary by lens.

    I have the capacity to put LTM mount lenses on my view cameras, so could set up similar circumstances there, but not so well with M lenses. I haven't really tried this yet, so have nothing to report from experience.

    A quick test: 50mm Summitar has an image circle of about 106 mm and focuses at about 110 mm when the flange is about 85 mm from the ground glass.

    a 75mm C/V Color Heliar has about a 104 mm image circle focused at just over 200 mm when the flange is 85 mm from the film.

    So it looks like both these lenses would cover your film. You can do the math to get reproduction ratios.

    Then there's the question of the close-up performance of any given lens you might try.

    Lee
    Last edited by Lee L; 02-13-2009 at 04:04 PM. Click to view previous post history.

  4. #4
    dpurdy's Avatar
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    http://cgi.ebay.com/For-Leica-Leitz-...1%7C240%3A1318

    That is what I was looking at and I see you are right in that the lens would be much farther from the film plane.
    Thanks
    Dennis

  5. #5
    Lee L's Avatar
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    That adapter is for Visoflex lenses, which have a different flange-to-film standard. There were not a lot of options for Visoflex lenses, and you'd have to find one of those for infinity focus to work. I recall 65mm, 90mm, 135mm, 200mm, and longer lenses designed for Visoflex that should work with this adapter. The item for sale is also apparently a LTM 39mm threaded mount, not a Leica M bayonet mount.

    Lee

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    2F/2F's Avatar
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    Hi, Dennis.

    First off, it looks like that adapter on E-Bay is for LTM lenses (AKA M39), not M glass.

    Then, it is made for Visoflex lenses. These lenses mount to a thick prism housing that attaches to the front of the rangefinder body, making it into an SLR. Thus, infinity focusing is possible on the 67 (or so they claim) because the Visoflex lenses are designed to be mounted significantly farther from the film than a regular LTM lens. If you mount a plain-ol' LTM lens, you will get close focusing only, and will have to do 98% of the focusing by moving the camera body forward and backward in relation to the subject, since the LTM lenses move forward and backward so little to focus. As for image circles, I don't know what they are. I'll be you could get some fun effects, though!
    2F/2F

    "Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."

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    Quote Originally Posted by dpurdy View Post
    I have just discovered that I can get an adapter for my Pentax 67 to make it take M series lenses. That is a very intriguing idea and I wonder if I would get a full circle of image on the 120 film or just what I would get. Anyone ever checked out the circle of light from an M series lens to see how large it is?

    Thanks
    Dennis
    Are you absolutely sure it's not Pentax 67 lenses to Leica M body (which would also include the Visoflex II and III housings? As a general rule, 35 mm lenses will cover 6x7cm at 1:1 macro or larger, not infinity. Exceptions include the 135mm Hektor, which will cover 9x12cm, probably 4x5" as well.

  8. #8
    dpurdy's Avatar
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    Ouch. I can't hide my ignorance. Sorry for my mistakes. I've never heard of Visoflex lenses. I guess I better do a bit more research.
    thanks again
    Dennis

  9. #9
    Lee L's Avatar
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    Quote Originally Posted by dpurdy View Post
    Ouch. I can't hide my ignorance. Sorry for my mistakes. I've never heard of Visoflex lenses. I guess I better do a bit more research.
    thanks again
    Dennis
    Don't apologize. We all know more now than when we woke up this morning. That's usually a good thing. And I now have some known options to try for macro work with roll film backs (or sheet film with greater extension).

    http://elshaw.tripod.com/Visoflex/Visoflex.html

    Lee

  10. #10

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    I've learned something, too - there is a Visoflex lens (39mm screw thread) to 67 body adapter:
    http://cgi.ebay.co.uk/For-Leica-Leit...hippingPayment
    Not sure how anyone would use it! At infinity, a Leica lens would probably give a circular image of 50 mm or so. There was a 65mm Elmar lens for the Visoflex which focused from infinity to 1:1, the mark 1 (which I have) is usually reckoned as being not quite as sharp at close distances as the mark II. If I was going to put any 35mm lens on a Pentax 67, I think I'd make it a 55mm Micro-Nikkor, one of the truly great macro lenses.

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