Oly IS focal length entry for legacy+teleconverter

Discussion in 'Adapted Lenses' started by redcannon5, Feb 28, 2013.

  1. redcannon5

    redcannon5 Mu-43 Rookie

    20
    Aug 4, 2011
    Edmonton, Canada
    Mark
    I can't seem to find a definitive answer on this.

    If for example, I attempt to handhold an adapted 300mm lens with a 2X teleconverter:smile:.. Which effective focal length should I enter for the appropriate stabilization?

    My guess is "approx" 350mm based on the focal length of the tele plus the flange to flange distance of the extension?..
     
  2. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Dara
    600mm. But don't expect miracles - that's an awfully narrow angle-of-view.
     
  3. JohnF

    JohnF Mu-43 Regular

    183
    Apr 1, 2010
    Oberursel, Germany
    No. 600 is the effective focal length due to the magnification effects of the extender.
     
  4. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    The IS should be set to the effective focal length, in this case 600mm. I have to agree with dhazeghi that at that long the IS would not be as effective. Worse in that you lost 2 stops of light with the tele-extender. I would highly recommend using a tripod or at least a monopod.
     
  5. redcannon5

    redcannon5 Mu-43 Rookie

    20
    Aug 4, 2011
    Edmonton, Canada
    Mark
    Thanks guys,

    This is correct. I put in a call to Olympus support to confirm, and after 5 min of "research", the tech said to use nearest effective focal length or above.

    I just wanted to know the principle.. I don't expect much from the IS at these lengths.
     
  6. speedandstyle

    speedandstyle Mu-43 Hall of Famer

    Glad to know that Olympus support can/will find answers for us if we need them. I have not shot that long on mine but I do have a 300mm adapted lens and the IS does help a bit. I estimate 2 stops worth. With a native 150mm it is good for 3 stops. Of coarse it could be that those are native lenses and not that it is half the focal length. Good luck and let us know how well it works for you.
     
  7. malmeida14

    malmeida14 Mu-43 Regular

    26
    Jul 17, 2012
    I don't know the principle, but I'm been playing around with long focal lens (F-Zuiko 300mm f4.5, F-Zuiko + 2x teleconveter and Samyang 800mm) and I notice that when I forgot to change the focal length from 50mm to 300mm or even from 300mm to 600mm the IS didn't work well, struggling to keep the image stable, when working the other way around the problems was equal. So I think it works even at 800mm (1600mm 35mm), but of course there are no miracles. This is particularly important for me since this are manual focal lenses, with a very shallow depth of the field, with the additional problem that my eyes are "very used" and working not so good, so it is very difficult to correct focus unless the IS works well.
     
  8. JohnF

    JohnF Mu-43 Regular

    183
    Apr 1, 2010
    Oberursel, Germany
    There is a point where you can't effectively hand-hold anymore, no IS can overcome large movements at high magnification. The IS needs to know the angle of view it needs to compensate for: a longer lens needs more correct tion than a shorter lens to achieve the same correction factor.

    The longest lens I have is a 600mm Sigma f8 mirror lens with T2 mount, but I also occasionally use a Leica 400 f6.3 Telyt-R with a Leica telextender for a 800 native focal length, 1600 mm effective focal length for 4/3. To be honest, anything over 300mm in anything but bright sunlight is a problem, even then I need at least 1/2000th exposure to ensure decent sharpness for critical work, action well above that. But that's me. :)

    At 400 and beyond, it's tripod time. No way to get around that and the you really need to turn off the IS then, since otherwise the camera will try to compensate for movement that isn't there and worsens sharpness. Further, at those focal lengths you can't get away with the usual cheap, lightweight tripod, but need a right and proper tripod that will not only support both camera and lens, but will help absorb vibrations that otherwise destroy sharpness. Berlebach wooden tripods excel at this,but are relatively small and heavy. I usually use a Manfrotto 028b with the longer lenses (usually with the Olympus E30 and battery pack attached to a Gigapan Epic Pro panoramic robotic tripod head. :)
     
  9. malmeida14

    malmeida14 Mu-43 Regular

    26
    Jul 17, 2012
    That's a problem that I have. My cheap tripod work "well" till I got this longer lenses. Putting in the EM-5 a 12s time lapse between press the shutter and shoot the picture, is not an option when trying to take bird pictures. It's time to buy a decent tripod and a remote shutter! I'm going to consider your set.