Mamiya TLR lens groups interchangeable?

Discussion in 'Medium Format Cameras and Accessories' started by dchan, Dec 19, 2012.

  1. dchan

    dchan Member

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    I have two lenses. One with excellently functioning shutter but rear lens group has spots all over it. The other lens has very clean glass but a hesitant shutter. Anyone know if the lens groups are interchangeable between two lenses without any issues?
     
  2. BMbikerider

    BMbikerider Member

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    I wouldn't risk it. Manufacturers are not well known for releasing essential data and you may end up with an unusual bit of glass that is about as usefull as a bucket full of holes. It may be possible to get the 'spotty' lens cleaned and go with that.
     
  3. MSchuler

    MSchuler Subscriber

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    I've had Flutot's Camera Repair do work on my Mamiya TLR lenses on the past and they might be able to help: http://flutotscamerarepair.com
    One caveat - last time I had them do work, they had a very long backlog.
     
  4. dchan

    dchan Member

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    Bmbikerider, You are probably right. I may just try it out and if it doesn't work clean out the spotty lens. Swapping them out is really easy so I can just as easily swap them back.

    Mshuler, Thanks for the link. I'll have to check their prices out.

    Anyone else have any thoughts?
     
  5. Gerald C Koch

    Gerald C Koch Member

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    This has been discussed on a previous thread. Lens manufacturers have been to make make unannouced modififications to a lens formula. So the two lenses may not be identical.
     
  6. Marc B.

    Marc B. Member

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    Carol at Flutot's almost always states that her forte is shutter repair...not lens work.
    If possible, she even asks that you not send the glass with the shutter, (she mostly does LF shutters).
    So, (in your case) with a TLR group, (which she also repairs), she would probably only be interested in
    repairing the lens-set with the bad shutter, rather then swaping the good glass out of the bad shutter.
     
  7. grahamp

    grahamp Subscriber

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    If you can do the exchange without removing the lens pair from the lens panel, it will probably work. Each lens has a slightly different focal length, and the pairs have to be matched. Sometimes this is done with shims between the front elements and the lens panel. There is an argument to switch the elements of both taking and viewing lenses, but if you do it, I'd try the critical one and test the result carefully to see that resolution is what you expect, and that the focus remains in sync.

    It's ultimately your call. Do get hold of the right lens wrenches before you start. There is always a risk of damage doing this sort of thing. You hear many tales of people doing front element swaps on these lenses. You don't hear about failures very often!
     
  8. revdocjim

    revdocjim Member

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    I don't know what this camera is worth to you but I would certainly try, especially if it is as easy as you say. I had a similar situation with two Mamiya 6 folders (the old 6). The one with the broken shutter had cleaner glass. In the end I kept one element from the dirtier lens and the rest were from the one with the broken shutter. It all worked out just fine and the finished product was better than either of its predecessors.

    If it doesn't work, just put it back like it was and get it professionally fixed or cleaned!
     
  9. xya

    xya Member

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    as stated above, get the right wrench and try it. normally the come off easily and you can as easily swap back if the result is not satisfactory. I swapped rear lenses with mamiyas several times and it was always a success. good luck
     
  10. Steve Smith

    Steve Smith Subscriber

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    I would try it too. I would move both the front and rear lens groups from the dodgy shutter to the good one. If you find any shims, keep them with the lenses they came from.


    Steve.
     
  11. Arcturus

    Arcturus Member

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    I've swapped the rear element of the taking lens for the rear element of the viewing lens on the 135mm and it worked out great.
     
  12. dchan

    dchan Member

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    Thanks for the input! I wasn't going to take the elements out or anything so I don't need any special tools since it just twists off. I only thought to swap the rear groups but swapping both front and back or taking and viewing is worth a shot as well. I'll try all the variations and shoot a test roll and if all else fails, I'll get the glass cleaned.
     
  13. steven_e007

    steven_e007 Member

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    I would set up a test -maybe cover a wall with newspaper (because of the fine detail in the print) clamp the camera ona good solid tripod and shot some test shots with a remote cable on a slow fine grained film with a wide aperture (a shallow depth of field shows up focussing issues much better) Then swap the lens elements and repeat.

    The trouble with putting a film through in 'normal' usage is that stopping down, camera shake and the fact that each image is different makes it difficult to spot subtle errors. Might be a long time before you hit the conditions that show up a focussing error.
     
  14. benjiboy

    benjiboy Subscriber

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    Are you sure the viewing lenses and taking lenses are the same quality ?
     
  15. Steve Smith

    Steve Smith Subscriber

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    Looking at my Mamiya TLR lenses, it would appear that both viewing and taking lenses are identical and are marked identically (apart from the serial number).


    Steve.
     
  16. grahamp

    grahamp Subscriber

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    There is one exception to the potentially interchangeable rule that I know about - the 80mm 'S' has a different viewing lens construction from the taking lens. The 80mm f3.7 uses a different (Copal) shutter and may also be non-interchangeable. This is not to say that the viewing lens is always as good for photographic purposes, but anecdotal evidence suggests that both optics are of similar quality.

    Graham