A7ii, IBIS and Macro Extenders

Discussion in 'Adapted Lenses' started by Tipton, Mar 27, 2017.

  1. Tipton

    Tipton TalkEmount Veteran

    359
    Jan 30, 2016
    Rae Leggett
    I use a Vivitar S1 90mm Macro with extender for my occasional amateurish handheld macro shots of flowers. IBIS will definately help there. With IBIS in my new A7ii, I can set the focal length of the lens I'm using. Should I set it to 90mm when I use the extender, or to the overall focal length?
     
  2. AlwaysOnAuto

    AlwaysOnAuto TalkEmount Hall of Famer

    Feb 17, 2015
    Why not try it both ways and see which works best for you?
    You're not going to break anything, you'll just find it harder to focus one way vs the other I believe.
    I've never used my extension tube on my A7ii so I don't know which will work best.
     
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  3. Hawkman

    Hawkman TalkEmount All-Pro

    Sep 10, 2013
    Virginia, USA
    Steve
    Hmmm, this is an interesting question, and one that one of the true experts in lens focusing here on the forum might be better able to answer. That said, I'll take a stab at it with my limited understanding....
    As I understand it, macro extenders do not change the focal length of the lens, but rather move the back of the lens farther from the imaging plane (the sensor) and thus change the focal point thereby enabling the lens to focus at closer distances to the subject (and consequently reducing the ability to focus at longer distances to the subject, i.e., no more infinity focus). Based on this, I would expect that for purposes of IBIS, as the focal length of the lens is the operative factor to be controlled since it affects the field of view and hence the relative movement of the subjects in view, then the presence of an extender should not affect the function of the IBIS as it does not change the focal length of the lens. Of course, as I don't have a body with IBS (much to my chagrin) I can't test my theory.
     
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  4. JMM

    JMM TalkEmount Regular

    186
    Jul 29, 2016
    John
    First thing is that focal lenght changes with focusing, hence 5 axes ibis works only with 8 pin lenses (via la-ea4) or 3 axes with other lenses. Other thing is that since you working with huge magnification, IBIS efficiency gonna be heavily stretched and you should try some huge numbers, as it's gonna be similar to supertelephoto.
     
  5. chalkdust

    chalkdust TalkEmount Top Veteran

    504
    Sep 25, 2015
    Bert Cheney
    Great question, Tipton. I am silently nodding my head in agreement with AlwaysOnAuto, Steve, and John. I do not have any extension tubes,so i suppose it is merely academic to me. But I am curious...
     
  6. Tipton

    Tipton TalkEmount Veteran

    359
    Jan 30, 2016
    Rae Leggett
    Well, I did some experiments. These are all of the same crocus at the side of my house. Jpegs straight out of the camera.

    The first is Sony A7ii + Vivitar S1 90mm Macro, handheld, with the extender attached, f/2.5. For those not in know, the extender for the "bokina" is not just a tube, it has glass in it, and adds a lot of weight. IBIS is OFF. 20170327-DSC00173.jpg

    For the next photo, same conditions, except IBIS is on, and set to 90mm. (different angle, too)

    20170327-DSC00187.jpg

    Now I mentioned the glass and weight of the extender for a reason. Those previous two pics are taken of a tiny flower at maybe 9 inches distance, but the whole thing is heavy. Camera plus lens is easily four pounds. It's easy to find focus but hard to keep it. This last pic, I took off the extender, left IBIS on, set to 90mm.

    20170327-DSC00202.jpg

    Now here you can see the difference in DOF. And this is from maybe 3 inches away. The thing is, it's a lot easer to use because the lens weighs half as much!
     
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  7. chalkdust

    chalkdust TalkEmount Top Veteran

    504
    Sep 25, 2015
    Bert Cheney
    Tipton, with respect to your original question, I think you are saying that the proper setting for macro is simply the focal length of the lens. Further, you are saying that for this lens handheld, you prefer using it without the extender due to the weight.

    Did I get that right?
     
  8. Tipton

    Tipton TalkEmount Veteran

    359
    Jan 30, 2016
    Rae Leggett
    Basically, yes. The extender adds too much weight to use handheld. On a tripod, I would use the extender and turn off IBIS.
     
  9. JMM

    JMM TalkEmount Regular

    186
    Jul 29, 2016
    John
    Uh, im not sure where that conclusion is coming from as 1 and 2 image is equally sharp, despite different focus, and 3rd one is blurred.
     
  10. AlwaysOnAuto

    AlwaysOnAuto TalkEmount Hall of Famer

    Feb 17, 2015
    Decided to try my PK-13 tube on my A7ii since I was playing with the bellows rig and it got me wondering.
    What would happen if I put the PK-13 on the Series E 100 lens?
    Would it turn it into that 'out of the budget' 105 Micro Nikkor I secretly yearn for?
    Here are two shots, first with the PK, camera on tripod, IBIS set at 100mm and turned 'ON'.
    Second is same shot only without the PK, just to check out the change of FOV for my own sake.
    DSC01705 (Large).JPG
    DSC01707 (Large).JPG
    The experiments will continue.
     
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  11. WNG

    WNG TalkEmount Hall of Famer

    Aug 12, 2014
    Arrid Zone-A, USA
    Will
    Hmmm, interesting extension experiment with the Series-E 100mm!
     
  12. mnhoj

    mnhoj TalkEmount Veteran

    226
    Aug 19, 2013
    A thread with Bokina, 100E and extenders got the blood flowing.
    So I busted out the PN11(pre-AI 105F4 micro?) and K-rings.

    I've never thought of changing the FL with extenders. Great question.
    Most of the time I'm on a stand with IBIS off.
    But curiosity has me scratching my head. ( :
    These are with a table top pod since it's dark here.

    The 100E on the PN11 at max. focus distance.
    38542775802_c1e6335e71_h.jpg
    DSC06662.jpg
    by john matsu, on Flickr

    100E, PN11 and K1-K3 rings at min. focus distance.
    24702496288_accf9afbbc_h.jpg
    DSC06666.jpg
    by john matsu, on Flickr
     
    Last edited: Nov 22, 2017
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