Is there any C-mount adapters that mount the lens right-side-up?

Discussion in 'Adapted Lenses' started by Jonathan F/2, Aug 2, 2012.

  1. Jonathan F/2

    Jonathan F/2 Mu-43 Hall of Famer

    Aug 10, 2011
    Los Angeles, CA
    Is there any C-mount adapters that mount the lens right-side-up? (UPDATED!)

    I just received my Fotga C-mount adapter, and found out it mounts the lens up-side-down. Is there any quality C-mount adapter that mounts the lens properly? I'm currently using a Pentax 25mm 1.4 and I have a Cosmicar 75mm 1.4 arriving soon as well. Should be fun. :wink:

    Has anyone tried this Yeenon adapter which lets you adjust the mid-point:
    ã€￾Yeenon】 C Mount to Micro 4/3 Mount adapter (can adjust the midline position) | eBay


    UPDATED! I was able to adjust my C-mount lenses by adjusting the screws on the mount. Here's quick picture:



    They're super small, so I had to use an exacto to loosen them. But after adjusting, my c-mount lenses are all in the proper mid-point orientation!
     
    • Like Like x 1
  2. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    I've got the same issue with my adapter which if I recall I got from Rainbow Imaging. Some have suggested that you might be able to rotate the mount on the lens itself. My 35mm lens has what appear to be three tiny set screws around the mount that might allow this, but I have yet to try it (mostly because I don't have a small enough screwdriver).

    My 75mm lens does not appear to have any mechanism to rotate the lens mount, and this is the one where the rotation is most annoying. I'm trying to learn to live with it, but that rotating adapter might be interesting. I just wish it were less than US$60.
     
  3. Jonathan F/2

    Jonathan F/2 Mu-43 Hall of Famer

    Aug 10, 2011
    Los Angeles, CA
    $60? It's listed for $46.99 with an 'offer' option. :wink:

    I'm thinking of putting a bid in, but I'm a little worried due to not having reviews out there.
     
  4. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    I was including the $15 shipping in my cost assessment.
     
  5. RobWatson

    RobWatson Mu-43 Hall of Famer

    Careful ... set srews on the rear of the lens may be used to set the backfocus. If so they will have some fairly stout loktite/thread locker and will be quite difficult to turn. If one screw shows then for sure they are for back focus adjustment so you may want to stop and leave the other screws alone.
     
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  6. DeeJayK

    DeeJayK Mu-43 Hall of Famer

    Feb 8, 2011
    Pacific Northwest, USA
    Keith
    Here's a pretty thorough review of a couple of adapters (one with rotation adjustment) which also includes some good general background c-mount lenses. Apparently, each manufacturer's lenses are different in terms of rotation vis-a-vis the mount, so an adapter that mounts one lens "correctly" might mount another "upside-down".
     
  7. Jonathan F/2

    Jonathan F/2 Mu-43 Hall of Famer

    Aug 10, 2011
    Los Angeles, CA
    Any recommendations for a cheap c-mount adapter that mounts the Pentax 25mm 1.4 right-side-up?
     
  8. powasky

    powasky New to Mu-43

    8
    Jul 31, 2012
    My Photodiox adapter came in the mail two days ago and mounts the Pentax 25 right side up.
     
  9. RobWatson

    RobWatson Mu-43 Hall of Famer

    No rotation adjustment?

    Just to show an example of how tricky it can be to find the rotation adjustment - Navitar 25mm F0.95 c-mount lens

    Same applies to their 17mm F0.95 lens. The 50mm lens adjustment is quite obvious.

    There are plainly visible two screw heads on the rear flange. These are used to fine tune the back focus distance. That entire piece unscrews to reveal how the c-mount threaded nose piece is mounted.

    <a href="http://minus.com/lufG1381GUDMc">
    <div align=center>
    http://i.minus.com/iufG1381GUDMc.JPG" width="400" height="300"
    </div></a>

    A wave spring can be seen upon which the silver threaed nose piece rests. The black part with the screws for setting the backfocus distance simply press the nose piece against the wave spring. The silver threaded nose piece is free to rotate.

    <a href="http://minus.com/lYfDBruO7qcIv">
    <div align=center>
    [img]http://i.minus.com/iYfDBruO7qcIv.JPG" width="400" height="300"
    </div></a>

    Kind of tricky to mount the lens to a camera/adapter and then press it into the adapter against the wave spring and rotate the lens body into the desired position. Practice with the adapter (no camera) until it becomes second nature.

    A quick check on any lens is to look for the spring action when pressing the lens into an adapter to identify the ability to make rotation adjustments so as to position the lens markings into the desired position.
     
  10. Jonathan F/2

    Jonathan F/2 Mu-43 Hall of Famer

    Aug 10, 2011
    Los Angeles, CA