Pentax lenses on Sony Full Frame

Discussion in 'Pentax' started by malcom_knight, Oct 25, 2013.

  1. Malcom, you should look into this adapter as it has 5 steps aperture adjustment that can work with DA type of lens that are without aperture ring. The one you posted only work with lens that have aperture rings. I have the adapter with aperture control for 5 steps. Both Pentax K to NEX adapters are a bit bulky. There is a similar adapter for the M42 lenses and it is even bulkier with a cylinder shape. I don't have the A7 but you can visit my blog page and see how I use Pentax K mount/M42 mount lenses with Sony NEX cameras.

    An alternative way to use the Pentax Full Frame capable FA mount lenses with current nex E mount is with Zhongyi Lens Turbo that is a focal reducer that cancels out the 1.5 crop factor on aps-c and the focal reducer adds 1 extra light of stop. The caveats lie in degradation on corner performance. The advantages are FF field of view and gain of 1 stop of light. You can look up Metabones speedbooster and the Chinese knockoff Lens Turbo. The reason that I mention Lens Turbo is that the adapter is almost like half the length of the Pentax K to NEX adapter.

    Using the FA 77 and 43 with the lens turbo is great on my nex 5n and so are the inexpensive SuperTakumar 55mm f/1.8, 35mm f/3.5 and 28mm f/3.5. The gain of 1 stop of light work especially well with slower lens as in f/3.5 and f/2.8.
     
  2. The Pentax K to NEX adapter is not small and you can see this picture with a FA 43mm for reference
    [​IMG]
    And the Leica M, LTM, Pentax Auto 110, Konica AR to NEX adapter are thinner in comparison
    [​IMG]
    They all work well in the NEX system and they should work with full frame lenses on A7/A7r in the FE mount. If you mount any DA lenses onto the A7/A7r (the FE mount), a crop mode is required if you don't want the vignette on corners.
    Out of all the traditional SLR lenses, the smaller adapter that I know are the Canon FD and Konica AR. The others are similar in size to the Pentax K adapter.
     
  3. I am studying the two adapters that come out with A7 and A7r. They will work with AF with Sony Alpha lenses in
    • Sony LA-EA3 $199 -- Use this adapter to attach Alpha A-mount lenses to your Alpha E-mount full frame camera body. It includes Auto Exposure support with aperture mechanism and a detachable tripod attachment.

    • Sony LA-EA4 $349 with built in SLT -- Attach Alpha A-mount lenses to your E-mount full frame camera body and enjoy full-time continuous Phase Detection AF while capturing stills and video with world's first full frame mount adaptor to be equipped with Translucent Mirror Technology™. Plus, aperture drive mechanism enables Auto Exposure with compatible A-mount lenses3.
    The latter will work with faster AF with phase detection. It is analogous to the LA-EA1 and LA-EA2 that work with Sony NEX (aps-c cameras).
     

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