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For those with new Panasonic bodies: 20mm f1.7 focus speed improved?

Discussion in 'Native Lenses' started by agentlossing, May 10, 2016.

  1. agentlossing

    agentlossing Mu-43 Hall of Famer

    Jun 26, 2013
    Andrew Lossing
    My GX85, for which I am eagerly waiting, has DFD capability. I had the Panasonic 20mm for a little while and loved the image quality but didn't love the focus speed, at all. I'm wondering now, however, whether I shouldn't give it another shot with this new camera body. Does DFD do anything measurable to cut down on the time to focus? I understand a large part of the 20mm's slowness is just a sluggish focus motor, and it wasn't especially prone to hunting in my experience, but it seems to me that it might at least eliminate some of that. Thoughts/experiences?
     
  2. Turbofrog

    Turbofrog Mu-43 Hall of Famer

    Mar 21, 2014
    What body in particular did you find it slow on?

    I have heard that it's quite slow on Olympus bodies, but I've never been able to replicate that since I've only had a GX1 and GX7 and it's okay on those (about on par or better with what I've experienced from Pentax DSLRs). Really though, I almost always use S-AF with the touchscreen to select a single high-contrast edge, and that works for me. Honestly, I'd be surprised if DFD did anything to improve its speed, but I guess that would be a pleasant surprise if it did.
     
  3. agentlossing

    agentlossing Mu-43 Hall of Famer

    Jun 26, 2013
    Andrew Lossing
    Both EM10 and GM5. I do find it a little too slow for my uses, but Street is one of those, so while I understand that it's not super duper slow in abstract, it was pretty slow for me.
     
  4. twokatmew

    twokatmew Mu-43 All-Pro

    Jun 1, 2012
    Lansing, MI, US
    Margaret
    I'd be interested in this info too. I've had a couple copies of the original 20, but I couldn't stand its sluggishness on Oly bodies in low light. That and the banding!

    Sent from my SM-G930V using Tapatalk
     
  5. agentlossing

    agentlossing Mu-43 Hall of Famer

    Jun 26, 2013
    Andrew Lossing
    I'm surprised no one has weighed in. This would be an exciting development to me if it improved.
     
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  6. Jonathan F/2

    Jonathan F/2 Mu-43 Hall of Famer

    Aug 10, 2011
    Los Angeles, CA
    I find the 20mm II a tad better, but not enough to be noticeably faster in real world use. I do prefer the better build quality though and it's supposed to be a little bit better with flare. I think the 20mm is my favorite lens, but I swapped it out for the 17mm mainly for the wider FOV.
     
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  7. Pili

    Pili Mu-43 Veteran

    224
    Jul 16, 2012
    Boulder, CO
    Alex
    It's still noticeably slower the other, newer lenses on my GH4 and doesn't CAF. But with that said, focusing is much more accurate on the gh4 then my em5 and is acceptable for casual shooting (i.e. not weddings...), imo.
     
  8. aidanw

    aidanw Mu-43 Regular

    116
    Nov 19, 2012
    Wellington, NZ
    The banding I saw frequently with the 20mm (I) on the EPM1, EPM2 and EM5 doesn't appear on the EM5 Mark II even at very high ISOs. Focusing is still sluggish though.
    I prefer the O17 f1.8 for focus speed, but the 20 just has a look.
     
  9. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    we have a GH4 at work, so I tested mine on that a couple of weeks back. If there is a difference between my GH1 and the GH4 its measured in eye blinks. But then unless you focus on your hand, then focus on the far side of the office, then refocus on your hand; focus is measured in eyeblinks anyway. The office is not bright and is a large open plan floor.

    Once you have acquired something then it just keeps on keeping on repeated focuses nearby FAST.

    The camera guy in our Media Production Team came from EOS and when he used it his first reaction was surprise and "WOW, this thing is fast". He thinks its faster than his EF40f2.8 which he likes ... so I keep coming back to expectation management.

    It is not an inner element focus lens, it moves the entire lens assembly. It does this with stepper motors. So there is an inherent technology and physics issue which isn't going to change. Its like buying a Toyota Yaris and expecting a firm ware upgrade will make it into a Mustang.
     
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  10. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    well I didn't "weigh in" because I generally find the subject an irritating one. Its like people fussing over hair splitting when there are fundamental reasons why its not going to change and why its really down to proper management of expectations. Inner focus lenses will always move a small (often single) element faster than a technology which moves the entire lens assembly in the old fashioned way. I find it annoying also because people seem to exaggerate the issue beyond anything one finds in numerous youtube comparisons with Oly cameras. It always feels like people blaming their equipment for their failure as a photographer. Part of being a photographer is knowing your gear and what its limitations are and how to work around the issues.




    Also a review by one of our own members:
     
    Last edited: May 11, 2016
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  11. agentlossing

    agentlossing Mu-43 Hall of Famer

    Jun 26, 2013
    Andrew Lossing
    You may find it irritating but I'd call it a flaw in Panasonic's design, not people's expectations! It's a testament to how great the lens is that we treat it as a top-tier optic and want for everything about it to be as good as the IQ. Obviously I'm going to jump at potential for it to be made better, but I understand that, as it doesn't really tend to hunt, DfD apparently isn't gonna help it much.
     
  12. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    A flaw in design ... right. Keep in mind that its an early design lens. One of the first native lenses. Its only flaw is that things got better after it. I've explained why it really can't be changed without a major upgrade to the physical issues. Which would then make the lens double in price (and probably people complain that it was better value before).

    You asked a question about speed and then complained when it wasn't answered then you don't like the answers others give (unless they support your view).

    It performs better than what Oly were offering at the time (the 17f2.8) and that lens is seldom held in as high regard as the 20 still is to this day, which indicates to me that the only flaw is in expectation of technology from the past.

    I feel its a matter of people love to wax on about the flaws in something and are eager to dismiss the positives. Bad News travels faster than good.

    None the less I've "weighed in" on your question as the GH4 has Depth from Defocus, I've said that it was indescernable and also given my views of why it has not improved much and is unlikely to improve. If you yourself find that you totally need nanosecond focusing and are unable to come to terms with the limitations of that tool then I advise you dismiss the lens as not being for you and stop holding a candle for that older design being upgraded by any firmware when its really a hardware issue.
     
    Last edited: May 11, 2016
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  13. svenkarma

    svenkarma Mu-43 Top Veteran

    566
    Feb 5, 2013
    mark evans
    The O17/2.8's autofocus is much better on a GX7 than the P20's was.
     
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  14. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    interesting ... would you mind munging up a quick comparison? I'm interested as that's not been borne out by any side by side I've ever seen.

    Do you know any tests which compare the 17 and the 20 for AF speed and accuracy on the GX7?



    at 4min in he says "autofocus speed seems to be on a par with the Panasonic 20mm" ... so again I come back to "expection management".
     
    Last edited: May 11, 2016
  15. agentlossing

    agentlossing Mu-43 Hall of Famer

    Jun 26, 2013
    Andrew Lossing
    Stand down, grumps ;) I understand your argument completely, but I still want it to be faster.
     
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  16. twokatmew

    twokatmew Mu-43 All-Pro

    Jun 1, 2012
    Lansing, MI, US
    Margaret
    It's also much better than the P20's on an E-PM1, E-PM2, E-PL5, E-M5 and E-M10.

    Sent from my SM-G930V using Tapatalk
     
    Last edited: May 11, 2016
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  17. pellicle

    pellicle Mu-43 All-Pro

    Feb 10, 2010
    Southport, OzTrailEYa
    pellicle
    faster would be nicer ... but if it was dearer or bigger then I'd probably keep what I have.

    as an aside, I find it interesting that both the 17f2.8 and the 20f1.7 are the same essential design of focus with the moving the entire lens group assembly while the 14f2.5 is not ... the more modern replacements are often twice the price and twice the size (as that English fellow David Thorpe observes).

    Myself I would never probably have come to like the 20f1.7 as much as I have were it not for me owning a compact body like the GF ... somehow I just never use it on my GH (where I normally use the 14-45 or longer). Which is odd.

    None the less (back on topic) I've not really found any difference on our GH4 here and just texted a mate who has the GF1 and a GX8 and he says the 20f1.7 seems the same to him on both bodies...
     
  18. agentlossing

    agentlossing Mu-43 Hall of Famer

    Jun 26, 2013
    Andrew Lossing
    The 17mm f2.8 seems to move focus a fair bit faster... but it hunts back and forth a lot more. The 20mm usually felt like it knew when it had attained focus.
     
  19. svenkarma

    svenkarma Mu-43 Top Veteran

    566
    Feb 5, 2013
    mark evans
    Nope. See recent 'GX-7 shutter stuck' thread :crying:. Also I long since sold the P20, partially for AF and rendering issues, but mostly because I just don't get on with the 40 equivalence focal length.
     
  20. Frankgr

    Frankgr Mu-43 Regular

    43
    Oct 18, 2014
    Slightly off topic and I don't want to hijack the thread but I have a question re the 20mm V2 panasonic. When I touch (with a lens cleaning cloth) the front element, it wiggles with a bit of movement. Is this 'normal' or a 'broken' / loose element ?

    Or maybe it's best to start a new thread to ask other owners
    Thanks
     
    Last edited: May 14, 2016