new adaptor rumor - focal length reduction but light amplification

Discussion in 'Adapted Lenses' started by pellicle, Feb 25, 2010.

  1. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    Real Name:

    over here I found this very interesting thread on this topic.

    The rumor suggests that the adaptor will reduce the focal length by 2 meaning that your 200mm lens will have the same view as a 200mm lens on a full frame camera.

    Now for those of us who have been used to 4/3 giving us x2 advantage in focal length (making a 200mm into a 400mm) this sounds a bit poor, but it brings with it the advantage that light gathered will be essentially doubled so that could mean an extra stop of brightness.

    Suggestions are that this could actually work well. A poster on that forum has suggested that this technology works well in Telescopes:

    Focal reducers are common in astronomy, you take a 2000mm f10 SCT lens and drop it down to 1000mm f5.0. Wider field, faster, etc. But you don't see them for camera lenses. You can get a well-corrected f5-f6.3 focal reducer for telescopes for about $150.00.

    it may introduce AF as well ...
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  2. BBW

    BBW Super Moderator Emeritus

    Wow, that sounds very promising to me. Thanks pellicle for bringing the news of possibilities over here!:thumbup:
  3. SimplyEd

    SimplyEd Mu-43 Regular

    Feb 10, 2010
    So I better stop selling my old fd lenses... mmm... looks like the price of fd f1.2 lenses will increase..... Good stuff.... I wonder how much would they sell it.
  4. noodlehaus

    noodlehaus Mu-43 Veteran

    Feb 14, 2010
    They already have, I'm just so happy I was able to grab a 50mm f/1.4 Canon FD for $35 off ebay. I think it's us MFT owners who're driving up the prices/demand.

    This adapter is something I'll save for :D
  5. Djarum

    Djarum Super Moderator

    Dec 15, 2009
    Huntsville, AL, USA
    Real Name:
    Since I dabble in astronomy..yes, there are focal reducers for telescopes. But they do have other inherent problems unrelated to photography. Like anything else, adding lens elements has the potential for light loss and added unforseen aberritions. Only time will tell if something like this could work for cameras.
  6. ahuyevshi

    ahuyevshi Mu-43 Veteran

    Feb 9, 2010
    Berkeley, CA
  7. cosinaphile

    cosinaphile Mu-43 All-Pro

    Dec 26, 2009
    new york city
    what this could do for the impoverished wide end of the legacy lens on ep1\gf1 experence is mindboggleing
  8. Brian S

    Brian S Mu-43 Top Veteran

    Apr 11, 2009
    My Nikon E3 uses reduction optics to produce a full-frame view on a small size sensor. The sensor would otherwise be at least a crop factor of 2x. It is big, as the optics have to sit in the image plane of the lens. The maximum aperture of the reduction optics is F4.8, but is made up by increased light at the sensor. The F-stop is built into the reduction optics.
  9. cosinaphile

    cosinaphile Mu-43 All-Pro

    Dec 26, 2009
    new york city
    brian what are you talking about, i need more info about what you posted , it seems fascinating

    pictures etc , never heard of this
  10. cosinaphile

    cosinaphile Mu-43 All-Pro

    Dec 26, 2009
    new york city
    copied this from an e3 fact sheet , great info brian , thanks

    "Nikon Reduction Optical System (ROS) achieves practically identical picture angles when the same Nikkor lens is mounted on either an E Series digital or a Nikon 35mm 135-format SLR camera, This avoids confusion when you switch between these two types of cameras on a shoot. High viewfinder magnification ensures easy, detailed viewing. The Nikkor wideangle, lens image that you see when setting up is what yen get, for assurance that the subject filling the viewfinder frame is completely captured in the final shot.
  11. Brian S

    Brian S Mu-43 Top Veteran

    Apr 11, 2009
    Still works!

    A 1.3million pixel full-frame camera from 1998...


    I use it for all of my camera projects.


  12. mowog6000

    mowog6000 Mu-43 Regular

    Mar 2, 2012
    Oregon City Oregon
    Real Name:
    Pat bailey
  13. songs2001

    songs2001 Mu-43 Top Veteran

    Jul 8, 2011
    Another use is that with a tele-convertor, sometimes you can get autofocus on manual focus lenses.
  14. LegacyLens

    LegacyLens Mu-43 Regular

    Apr 25, 2012
    We do not need a stinkin' lathe THATS WHAT GLUE IS FOR OOH-RAH! :rofl:
  15. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Real Name:
    Perhaps. But I'm not sure whether the results would be worth the effort:

  16. CUB

    CUB Mu-43 Veteran

    Apr 19, 2012
  17. RSilva

    RSilva Mu-43 Regular

    Oct 24, 2011
    I hope this adapter comes true. Would love to be able to use my wider lens fully. Thanks for the post, I didnĀ“t know such thing existed.
  18. ekoe

    ekoe Mu-43 Regular

    Sep 26, 2010
    User "Overflow" has done some work with focal reducers and posted about his progress over in the forums. You can see the results he got here: The ol' telecompressor discussion....
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