Adapter Question

Discussion in 'Adapted Lenses' started by rayvonn, Oct 4, 2017.

  1. rayvonn

    rayvonn TalkEmount Regular

    60
    Jan 3, 2016
    Apologies if this sounds a bit naive or silly, but it's something I'd like to know and here's a good a place to ask as any.

    Is there an adapter which is 'thin', or makes you feel that you are connecting your adapted glass to your A7 natively? Or to put it another way, I have a Takumar 50mm F1.4. Lovely lens of course and lovely size - but the size isn't lovely when I add it onto my camera with my K&F adapter. The adapter's great but the lens looks huge, almost ungainly when attached to it, especially when imagining it on an original film camera.

    I do appreciate that this is truly a first world problem in these troubled times and that maybe the answer's 'no' - but I thought I'd ask.
     
  2. firemist

    firemist TalkEmount Regular

    162
    Dec 4, 2015
    Rayvonn,

    Your Takumar lens was designed to focus at infinity on a film Pentax SLR camera. The flange focus distance for Pentax SLRs is 45.46mm, meaning the distance from the lens mount ring to the film (or sensor these days) has to be just that distance, 45.46mm for your Takumar to focus to infinity. However, the flange focus distance for Sony E mount is 18mm. Therefore, in order for your Takumar lens to focus at infinity on your A7, the adapter has to be 45.46-18=27.46mm thick (just over 1"). There is no escaping this.
     
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  3. AlwaysOnAuto

    AlwaysOnAuto TalkEmount All-Pro

    Feb 17, 2015
    Rayvonn - I have the same complaint about the Nikon adapter I use, but there's no getting away from it.
     
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  4. bdbits

    bdbits TalkEmount Top Veteran

    916
    Sep 10, 2015
    Bob
    Yep, it's all about the flange distance. So if you want thin adapters, you need a mount that is as close to 18mm as you can without quite getting there, as the adapter is going to add some thickness. There is a nice chart at Flange focal distance - Wikipedia that lists flange distances. Leica M is a popular choice if you want relatively thin adapters and smallish lenses, but can have some issues particularly in the corners for very wide-angle lenses.
     
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  5. WNG

    WNG TalkEmount Hall of Famer

    Aug 12, 2014
    Arrid Zone-A, USA
    Will
    In order to have the least added bulk for you adapted vintage lens experience, you'll have to seek out lenses from camera systems with either no mirror box, ie. range finders, or a large aperture prime from an Olympus Pen-F. The Leica L39 mount has a very small 1/2" (12.5mm) thick adapter for E-mount. The Pen-F adapter is even less. I believe the Olympus Zuiko Pen-F 40mm f/1.4 1/2-frame lens will work on the full frame A7.
     
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  6. rayvonn

    rayvonn TalkEmount Regular

    60
    Jan 3, 2016
    Looking back on my question and the answers given, it seems the Takumar was one of the worst cases I could have provided for seeking a thinner adapter given the flange focus distance. I can see though that the best chances of using a thin adapter would be with Leica or Contax rangefinder lenses as well as Canon and to a lesser extent Nikon rangefinder lenses. I really appreciate the responses, including that Olympus tip, many thanks everyone..