Roxsen Focal Reducer Glass Unscrewed...

Discussion in 'Adapted Lenses' started by tjdean01, May 11, 2015.

  1. tjdean01

    tjdean01 Mu-43 Top Veteran

    842
    Feb 20, 2013
    The focal reducer is no longer producing crisp photos as it once was. I've tried a couple different lenses. And it's not the camera as the GM1 is doing great with the hollow adapters. Does anyone know how I should screw this adapter to make it work again? I kind of like using my 50/1.7 as a 35/1.2...a FL near which m4/3s doesn't have much to choose from.
     
  2. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
  3. RnR

    RnR Mu-43 All-Pro

    Sep 25, 2011
    Brisbane, Australia
    Hasse
    I didn't think any of the speedbooster alternatives had infinity adjustments? All the alternatives have different designs and come from a different factory.
     
  4. eteless

    eteless Mu-43 All-Pro

    Jun 20, 2014
    Different optical design, same principal behind them. I imagine all of them would have adjustment of some kind built into them.
     
  5. Petrochemist

    Petrochemist Mu-43 Top Veteran

    655
    Mar 21, 2013
    N Essex, UK
    Mike
    There is a locking similar screw on my RJ version. I'm not going to play with it though!
     
  6. HarryS

    HarryS Mu-43 Top Veteran

    921
    Jun 23, 2012
    Midwest, USA
    Yes, they can be adjusted, and they can come loose.

    I had to undo the set screw and move the lens assembly on my ebay focal reducing adapter just so it wouldn't hit the shelf above the sensor on my EM5. It didn't seem to affect the sharpness much (which I thought was acceptable for a $90 rig), and I could still get infinity focus. Someone else at the time opined that there was really no factory calibration on these clone models.

    It works well with my FD50, FD85, and FD135. Results with my 35mm and 28mm's were never good but those lenses sucked on hollow adapters too, so I don't think the placement of the reducer lenses was a factor.
     
  7. tjdean01

    tjdean01 Mu-43 Top Veteran

    842
    Feb 20, 2013
    So, HarryS, for me to "fix it," I just twist it and play with 'er?
     
  8. HarryS

    HarryS Mu-43 Top Veteran

    921
    Jun 23, 2012
    Midwest, USA
    If your adapter used to give good results, you should be able to trial and error it back into alignment. Mark the lens ring and adjust it in 1/4 or 1/2 turn increments while taking test shots and keeping notes.

    Mine only had about 3 turns to play with. At the limits it would either hit the camera body or hit the back of my FD lens. In retrospect, it's a POS but I kind of liked the results.
     
  9. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    It's funny, I was thinking kind of the opposite - considering the $90 price tag, the build quality seemed shockingly good to me, especially considering all the QC problems I hear about $350 Speedboosters. I don't use it as much as I should, but it mostly lives full time on a couple of my Canon zooms, or when I feel the need to turn my Takumar 50mm/1.4 up to ludicrous speed...