Stupid me? Extension Tubes

Discussion in 'Adapted Lenses' started by WT21, Oct 5, 2011.

  1. WT21

    WT21 Mu-43 Hall of Famer

    Feb 19, 2010
    Boston
    I bought a set of cheap extension tubes off eBay. I just realized, though, that now my native lens AF won't work. Am I missing a trick with these? Do you pre-focus the lens (to infinity or MFD) and then pop in the tube (and then focus by moving the camera back and forth). Maybe I'll just get a real macro lens instead of the tubes.
     
  2. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    You should only be using the extension tubes for macro, so you shouldn't need AF. At close macro focus AF is pretty much useless anyways. Just swaying a little bit forward or backwards can often fine-tune your focus, nevermind the focus ring.

    A dedicated macro is still best though. I assume your extension tubes are for mFT? If you adapt any macro lens to mFT, then you will still be able to use the extension tubes as well and get even tighter macro.
     
  3. WT21

    WT21 Mu-43 Hall of Famer

    Feb 19, 2010
    Boston
    Yes, mFT macro tubes, but shouldn't the lens itself be focus to max or min distance? I tried using the 14mm with all 3 tubes, and couldn't get anything resembling in focus, though it could with just one tube.

    It's all new to me, so I've got lots to learn. Thanks for the reply.
     
  4. G1 User

    G1 User Mu-43 Veteran

    411
    Jul 20, 2010
    The distance on the lens... If it is a macro lens.... should be at the closed distance, 1:2 typically on older ones... but anywhere will work.

    as mentioned by Ned, just move back and forth to focus... if you real close (all 3 tubes), you will need a tripod, as you will be inches away and over 2x magnification or better.

    ISO 800+ and f/3.5-5.6 as a start.
     
  5. Sammyboy

    Sammyboy m43 Pro

    Oct 26, 2010
    Steeler Country
    The real problem is focus by wire. You don't know where the internal elements of the lens are (no visual confirmation due to lack of focus scale), the lens my be set (focused) at infinity, you add 14mm extension tube between the lens and body and you can no longer use focus by wire. So if the lens is at infinity, there is no way to know where it is at, and you expect to get within say 4'' of the subject, in reality the focus point may be at 48". This is the problem with focus by wire. For best macro results use a macro lens or achromat close-up lenses. Perhaps Olympus will release the extension tubes with the required electric contacts.
     
  6. stratokaster

    stratokaster Mu-43 All-Pro

    Jan 4, 2011
    Kyiv, Ukraine
    Pavel
    And also there is no way to control the aperture and get reasonable DOF for macro shots.
     
  7. WT21

    WT21 Mu-43 Hall of Famer

    Feb 19, 2010
    Boston
    I realized all of this just as I put on the macro tubes and tried rotating the focus ring, lol. Oh well. At $15 for the tubes from China, it's not work sending them back.
     
  8. shnitz

    shnitz Mu-43 Top Veteran

    989
    Aug 25, 2011
    Austin, TX
    The problem with using a 14mm for macro is that you'll have to be incredibly close to get focus. I tried putting my 28mm on a Nikon D80 with extension tubes, and I pretty much had to have the front element touching the subject to get focus. Try a longer lens, like your 45mm. Or, use the extension tubes with your OM adapter and Rokinon 85mm.
     
  9. WT21

    WT21 Mu-43 Hall of Famer

    Feb 19, 2010
    Boston
    I am afraid the Rokinon on extension tubes would break the mount off. I will try the 45mm. That would give me a longer wroking distance.
     
  10. tlucmpla

    tlucmpla New to Mu-43

    6
    Aug 3, 2011
    Singapore
    I saw this chap selling mFT extension tube. I was keen to try it out on the 45mm f1.8. wondering how it will work

     
  11. Declan

    Declan Mu-43 Regular

    anyway, i wonder what different any make between using:
    -raynox Vs
    -extention/converter (genuine one)

    thanks