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To those who tested the Olympus 40-150 f/2.8 -> para/varifocal?

Discussion in 'Native Lenses' started by owczi, Oct 13, 2014.

  1. owczi

    owczi nareteV 34-uM

    Hi all,

    There don't seem to be many tests of the new 40-150 available yet and in those out there already, I couldn't find this info. Of those who have used it or otherwise know - can someone tell me whether the focus point floats or rather remains constant when zooming?

    I wasn't paying THAT much attention to this until I did some video recording with the Lumix 35-100 f/2.8. Not helpful at all with manual focus when you have to re-frame a little bit while recording.
     
  2. Promit

    Promit Mu-43 All-Pro

    Jun 6, 2011
    Baltimore, MD
    Promit Roy
    I would be very surprised to get a parfocal lens out of Olympus.
     
    • Like Like x 1
  3. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    Fwiw, the focus point of the 12-40mm Pro does change noticeably when zooming (contrary to some other forum posts I read).

    Barry
     
  4. Bokeaji

    Bokeaji Gonzo's Dad O.*

    Aug 6, 2011
    Austin, TX
    meaning... focus at 40, zoom to 150, and now its not in focus anymore?
     
  5. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    Yes, that is the right test.
    Preferably at widest aperture. A few focus distances may have to be checked.

    Barry
     
    • Like Like x 1
  6. sgreszcz

    sgreszcz Mu-43 Veteran

    439
    Oct 7, 2012
    Is the p35-100 2.8 par focal? I thought I saw a Vimeo or youtube video showing tests, but I can't remember if it was or not. What about the 12-35 and 12-40?
     
  7. owczi

    owczi nareteV 34-uM

    The 35-100/2.8 is definitely varifocal - this is the slight annoyance I described in the context of video. I don't own the 12-35, only the 12-40. I've read somewhere that it's parafocal but I don't think so - need to check, pretty sure it's not. As I said, to me this is most important with MF / video (at the widest aperture). Your mileage, as they say, may vary.
     
  8. Mat - MirrorLessons

    Mat - MirrorLessons Mu-43 Veteran

    274
    Mar 10, 2013
    Turin
    The simple solution for this is first set your focus point at the longest focal length, then zoom out, start record and zoom in.
     
    • Like Like x 2
  9. Geoff3DMN

    Geoff3DMN Mu-43 Veteran

    I always thought the term was parfocal, not parafocal.

    After googling I'm more confused than before. Help?
     
  10. sgreszcz

    sgreszcz Mu-43 Veteran

    439
    Oct 7, 2012
    True mat! I have this test and a lot more tests I need to do with my cameras and lenses :)

    By the way, your web site is an awesome resource an I love how you cover all mirrorless brands and do your comparisons looking from a practical or end user's point of view rather than just charts. I also like how you also do some video tests (including any stabilisation). Keep up the good work!
     
    • Like Like x 1
  11. Mat - MirrorLessons

    Mat - MirrorLessons Mu-43 Veteran

    274
    Mar 10, 2013
    Turin
    Thanks :) I just test it with the MZ 40-150 and it does the same, if you set your focus point a the shortest focal length then zoom in, it will loose focus.
     
  12. WT21

    WT21 Mu-43 Hall of Famer

    Feb 19, 2010
    Boston
  13. Whtrbt7

    Whtrbt7 Mu-43 Regular

    195
    Jan 7, 2014
    The 12-40 Pro is par focal. I'm willing to bet the new 40-150 Pro is too since the design looks to be par focal.
     
  14. kwalsh

    kwalsh Mu-43 Top Veteran

    775
    Mar 3, 2012
    Baltimore, MD
    No, the 12-40 is most definitely not parfocal - but it pretends to be. Optically it is varifocal, but as you zoom it moves the focus group to compensate and thus it appears to act parfocal. This is one of the benefits of focus by wire - you can play tricks like this. However, for many lenses that do this the process is neither perfect nor smooth and can cause issues when zooming for video. You can see this sometimes with the 12-40 if zooming quickly - it goes out of focus and then snaps back into focus. All of this in MF mode using the clutch ring such that if the lens were optically parfocal you shouldn't see any changes in focus. The other way you can clearly tell it is playing this trick is to put your ear to the lens when zooming. With the power off you hear nothing but the zoom ring moving, with power applied you can clearly hear the focus group motor moving as you zoom.

    I suspect the 40-150 will not be truly parfocal either, but they'll probably play the same electronic focus trick to make it act like a parfocal.
     
    • Like Like x 1
  15. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    My 12-40mm does not re-focus when zooming, at least so far I've noticed.

    Barry
     
  16. Sammyboy

    Sammyboy m43 Pro

    Oct 26, 2010
    Steeler Country
    Neither does mine ... manual focus at 12mm with 2x TC then zoom to 40mm, focus is right on.
     
  17. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    I mean mine loses focus and does not refocus...

    F2.8, S-AF... focus on the large letters on a Amazon shipping box 6ft away at 12mm, then zoom to 40mm... It's now slightly out of focus.

    I've noticed it at other distances as well.

    Barry