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Fast AF: Is it the body or the lens?

Discussion in 'Olympus Cameras' started by robertro, Nov 1, 2011.

  1. robertro

    robertro Mu-43 Veteran

    Apr 22, 2010
    Fast AF: Is it the body or the lens?

    I've been reading every report I can on the latest M4/3 equipment to try to determine whether Olympus has greatly improved the AF performance over the E-PL1 and E-PL2 cameras to the new 3 series, and I must say, I'm confused.

    It seems that every report of "lightning fast focus" leads back to either the 14-42 MSC lens or the 12/2 or the 25/1.4 or the 45/1.8.

    I'm beginning to think that (beyond the long-awaited focus assist light) that the differnces in the bodies are greatly overshaddowed by the differences in lenses.

    Anyone have any experiences they'd like to share?
  2. krugorg

    krugorg Mu-43 Hall of Famer

    Jul 18, 2011
    Minnesota USA
    Both. :biggrin:

    It's a lowest common denominator thing, in my opinion - they camera will perform up to the point where they hit the bottleneck, whether it is lens or body.

    I have a mix of older and newer lenses, and an E-P2 and E-P3. The 12mm is fast on my P2, but noticeable faster on my E-P3. My E-P3 seems a bit sluggish with the 20/1.7 mounted, only slightly faster than when it is on the E-P2.
  3. Jonathan F/2

    Jonathan F/2 Mu-43 Hall of Famer

    Aug 10, 2011
    Los Angeles, USA
    I do have the 17mm and I believe the E-PM1 and E-PL2 aren't that far apart in speed. Where my E-PM1 does shine is in low light with the AF assist illuminator, the shorter shutter blackout and the faster burst speeds (E-PM1/E-PL3). To give you an idea though, I feel pretty comfortable shooting my 45 1.8 and 12 f2 on the E-PL2. So if you're deciding between a new lens or body, I'd lean towards glass first!
  4. kevinparis

    kevinparis Cantankerous Scotsman Subscribing Member

    Feb 12, 2010
    Gent, Belgium
    the answer is both

    faster processors and more sensitive sensors in the bodies make decisions quicker, and faster motors and lens designs that move as little glass over the shortest distance all contribute to faster AF

    in all micro 4/3 rely on Contrast detection... which obviously requires at least some contrast in the subject and then an iterative process of adjusting the focus backwards and forwards to achieve the maximum contrast - which equals focus

  5. ~tc~

    ~tc~ Mu-43 Hall of Famer

    Oct 22, 2010
    Houston, TX
    IMHO, this is an area Oly dropped WAY behind Panny on, and a significant reason I bought a GF1 instead of a EPL1, and it took them way too long to catch up.

    The original kit lens was VERY slow, compounded with the slightly slow bodies, it equated to glacial AF speeds. They improved the lens, then improved the body, and are now back to improving the lenses to take advantage of the speed available from the body, which I guess is a long way of saying, the further down that curve you are, the faster your AF is going to be, obviously, new lenses on the newest body will be the fastest AF.

    Lenses like the 20/1.7 are too good otherwise to go with a different option (oh no, here come all the PL25/1.4 people, run!), so your only chance of faster AF with those lenses is the newest body, so that's how I would go ... in the end, only you can decide if it's significant TO YOU, and it's pretty simple to test. Take your body and lens into a store, and ask to try out the newer body with your lens.
  6. Even the old E-P1 will get a good boost by fitting it with a new(er) internally focusing lens. As had been said, the question of body or lens for improvements in AF speed is answered with a little from column A, and a little from column B.
  7. phigmov

    phigmov Mu-43 Hall of Famer Subscribing Member

    Apr 4, 2010
    I wondered the same thing - when I got my e-pm1 with kit 14-42 mk2 I put that onto my e-p1 and noticed immediate speed improvements.

    Conversely, the 17 & 20mm didn't feel much faster in general use on the e-pm1 except for low light when the AF-Assist light helped illuminate the target.

    I'm hanging out for the 45 f1.8 so I can get a more modern low light lens (the 25mm option is just way too pricey at the moment).

    I really really hope 'peaking' of some description comes in a firmware update so I can make better use of my Nikkor f1.2 and Pen F Zuiko f1.4 for low light manual shooting.
  8. ~tc~

    ~tc~ Mu-43 Hall of Famer

    Oct 22, 2010
    Houston, TX
    Does the EPM1 use the same high speed sampling rate as the EP3, GH2, and G3?
  9. DDBazooka

    DDBazooka Mu-43 Veteran

    Sep 3, 2011
    Many have pointed out on DPReview that the Panasonic cameras perform better with the 20/1.7 than the PENs. YMMV though.
  10. Ned

    Ned Mu-43 Legend

    Jul 18, 2010
    Alberta, Canada
    Both body and lenses can affect AF speed. However, your lens affects AF speed far more than anything else. So of course, if your body is "capable" of achieving lighting fast AF, it won't be able to with a slow focusing lens... no matter how capable the body is.

    With the AF speeds of new bodies there's no big difference anymore between brands and models anyways. I think the key point of the new AF system of the PENs is simply that it's now below par to DSLRs. Nobody can any longer claim that mirrorless cameras are "crippled" as a choice over DSLRs because of slower AF. That simply isn't true anymore.

    Your actual AF speed is still going to depend on your lens, just like on your DSLR. What the fast AF speed of the new PENs means is that your body will not be a limiting factor.
  11. dhazeghi

    dhazeghi Mu-43 Hall of Famer Subscribing Member

    Aug 6, 2010
    San Jose, CA
    Same as the E-P3. Similar to the GH2, G3 and GF3, but not identical.

  12. robertro

    robertro Mu-43 Veteran

    Apr 22, 2010
    Still looking for some real data....

    I appreciate the comments, they have given me some food for thought.

    I've been looking for an excuse to upgrade my E-PL1 to the current generation of bodies, but significantly faster AF does not seem to be it. I'll see if I can try an E-PM1 or E-PL3 out somewhere nearby.

    Considering how important AF is to these cameras, I'm surprised that none of the review sites have begun doing standard tests of AF speed under different typical scenarios.
  13. The only reason I would have to trade my E-PL1 is the occasional frustration with the control interface. Other than that I find it hard to justify an upgrade for what it might cost to do so.
  14. dhazeghi

    dhazeghi Mu-43 Hall of Famer Subscribing Member

    Aug 6, 2010
    San Jose, CA
    It all depends on how you compare. An E-PL1 kit will be much slower than an E-PM1 kit. Part of it's the body, and part is the lens, but the improvement is real.

    It's difficult to measure times sufficiently accurately for meaningful tests. Fixing a 'typical' scenario is also not as easy as it sounds.

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