Why are the MD Nex adapters so big?

Discussion in 'Adapted Lenses' started by swanseastu, Jun 17, 2013.

  1. swanseastu

    swanseastu TalkEmount Rookie

    Apr 19, 2013
    Im getting a nice collection of Rokkor MC / MD lenses together now (thanks to this site for all the great info!) but am frustrated by the size of the MD > Nex adapters.

    Im sure there is a reason, but for example my LM > Nex mount is a fraction of the size of the MD> Nex mount, thus every MD lens I put on my Nex extends the lens by over an 1 "

    My next planned purhcase when I can find one at the right price if for the rokkor 50mm 3.5 Macro, and with the adapter and tube, will make it pretty big....

    So, my question is why are they so big?
  2. xXx1

    xXx1 TalkEmount All-Pro

    Jan 15, 2013
    It is because of registration distances. SLR has got a mirror that takes about height of film/sensor so SLR lenses are designed to be mounted about 45mm from film plane. Nex adapters are roughly 25 mm in thickness (45mm-20mm).

    LM is mirrorless rangefinder with much smaller registration distance so the adapter is smaller too.
  3. jai

    jai TalkEmount Top Veteran

    Feb 4, 2013
  4. Jefenator

    Jefenator TalkEmount Top Veteran

    Nov 23, 2012
    Oregon, USA
    Real Name:
    Well, what do you know? Leica R and Nikon F - the two I use most - are two of the longest (at least for legacy 35mm film SLRs).

    IME the more compact SLR lenses are really not so bad when adapted. Some even fit with my flip-down case!

    Will be hard to compete with rangefinder lenses, though (or native e-mount - probably not a coincidence I wind up mostly using those on road trips).
  5. jai

    jai TalkEmount Top Veteran

    Feb 4, 2013
    Yeah, and you can see from that chart why Olympus Pen F and Leica M mount lenses are so compact mounted on the nex.