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Olympus Pull Back Manual Focus Ring Accuracy

Discussion in 'Native Lenses' started by AG_Alex2097, Jun 20, 2016.

  1. AG_Alex2097

    AG_Alex2097 Mu-43 Regular

    157
    Dec 18, 2015
    Alex S.
    I've noticed something rather odd, i'm not sure if it's just my lens, or the way it works, but whenever i pull back the focus ring on my Olympus 12mm f/2.0 and manually focus, the focus isn't smooth and happens in steps, making it impossible to accurately focus on something.

    The problem isn't present when i use the fly by wire manual focusing method however, using fly by wire it's really smooth without any issues.

    I was wondering if something's wrong with my lens, or if other people have the same issue? :/
     
  2. alex g

    alex g Mu-43 Top Veteran

    549
    Mar 30, 2016
    New York / Bath
    No, nothing wrong with your lens - that's just the way it is! I agree it's rather odd, but I think it's a limitation of the kind of rotary encoders which modern lenses use. The focus ring has a higher gear ratio in 'fly by wire' mode (with the ring pushed forward) so the steps are less apparent (although they are still there, just smaller). I believe that it's Olympus intention for 'snapshot mode' (with the ring pulled back) to be used when 'shooting from the hip', estimating focal distance by eye and dialing it into the lens with the aperture reduced to give enough DOF to cover any inaccuracies.
     
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  3. AG_Alex2097

    AG_Alex2097 Mu-43 Regular

    157
    Dec 18, 2015
    Alex S.
    I see, thank you for the information! I like using the pulled back focus ring, it's nicely damped, guess i'll just have to sway a little back and forth to nail that focus :p
     
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  4. robcee

    robcee Mu-43 Veteran

    289
    Jan 10, 2016
    Toronto
    Rob Campbell
    I think the 12mm has the most noticeable stepping effect of the manual focus lenses from Olympus. The 17mm and PRO 12-40, 40-150s don't exhibit as obvious a jump between focus points.

    The 12mm was the first of their lenses to offer this feature and I think they improved on the implementation in later lenses.
     
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  5. alex g

    alex g Mu-43 Top Veteran

    549
    Mar 30, 2016
    New York / Bath
    I don't have the 12, but I do notice it on the other Olympus lenses. It's inevitable when using a digital encoder with such a small travel. But it is possible that the encoder resolution was lower on the earlier models, as you suggest.
     
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  6. AG_Alex2097

    AG_Alex2097 Mu-43 Regular

    157
    Dec 18, 2015
    Alex S.
    Interesting information, glad to hear they improved it on later lenses, i don't own any other Olympus lenses that have the the pull back ring, but on the 12mm i've sometimes found it to be hindering because of the rather large steps (close up photography), curious if it would still hinder me on the newer rings
    Does it bother you on any of the lenses you own? (Other than the 12)
     
  7. alex g

    alex g Mu-43 Top Veteran

    549
    Mar 30, 2016
    New York / Bath
    It doesn't really bother me, mainly because I rarely use the feature. :) I agree with you that the action feels nicer and more damped when pulled back, so I would prefer to use it in that position for that reason alone, but unfortunately that's not generally how I shoot. I usually have the camera in manual focus mode with a button assigned to AF, which lets me focus quickly on the subject with the AF and then tweak with the focus ring between successive shots, without triggering the AF each time. I find it also makes changing to manual-only lenses more intuitive. I've only used the 'snapshot' focus mode at times where I've been wanting to be super-stealthy on the street and not even bring the camera to my eye, and in those cases, the inaccuracy of my range guesstimate is going to be far more of a limiting factor than the steppiness of the focus ring! :)
     
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  8. AG_Alex2097

    AG_Alex2097 Mu-43 Regular

    157
    Dec 18, 2015
    Alex S.
    Ah i see, alright, thanks for the heads up! :)
    I've recently seen the light of a dedicated focus button as well, provides a lot more control over the AF, but twisting that focus ring myself brings just that tiny bit of extra enjoyment in photography for me ^^
     
  9. alex g

    alex g Mu-43 Top Veteran

    549
    Mar 30, 2016
    New York / Bath
    I totally agree with you — there's a unique pleasure to be had from pulling a nice manual lens into focus... I'm the proud owner of one of the Voigtlander lenses, and it truly is a tactile delight. And it wasn't that long ago that practically all lenses were built like that. But it's a case of swings and roundabouts - AF necessitates a level of indirection between input and output, which inevitably takes away some of the joy of the process, but we can't deny its usefulness! Personally I think that Olympus have reached a good compromise with their focus ring clutch — arguably it's as close to the 'real thing' as is possible without inventing new and expensive technology. I just wish that we were given an option to select between accelerated/linear law for the 'fly-by-wire' focus ring — currently it's so hard to know by feel exactly how much focus input you've applied.
     
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  10. AG_Alex2097

    AG_Alex2097 Mu-43 Regular

    157
    Dec 18, 2015
    Alex S.
    Yes! I love olympus's approach to it and i hope they add it on every future lens (unless technically limited like the 8mm PRO), but i agree with ya, feeling the focus is what makes a dedicated focus ring so much better than a super soft fly by wire, i never thought about the idea of accelerated input, seems like a nice thing to get that fine tuning! :eek: