Focus speed across various systems

Discussion in 'This or That?' started by yakky, Jan 2, 2014.

  1. yakky

    yakky Mu-43 Top Veteran

    Jul 1, 2013
    Being stuck indoors that past few days I had a little while to do a simple and rather unscientific focus accuracy test. I recently purchased an X-E1 and was wondering how it held up to an SLR and M43.

    Test procedure:
    -Set min shutter speed to 1/250
    -Set lens wide open
    -Set to spot focus single (AFS)
    -Snap pictures of toddler running around like a banshee. No prefocus, just make sure the focus zone was on target and mash the shutter button down
    -sample set is ~50 pictures each, shot indoors on a mostly cloudy day using available light, most cameras were shooting >ISO 1600 wide open

    The results - shots completely in focus
    Fujifilm X10 28mm eq- 18%
    Fujifilm X-E1 18-55mm @18 - 80%
    Olympus E-PM2 Pan 20mm - 81%
    Nikon D5100 35mm - 87%
    Sony RX100 28mm eq - 89%

    What was interesting is the Oly never completely missed, 100% were good enough for small prints. I was completely surprised at how well the RX100 did. If I had used AFC, the results would probably be very different as that mode is useless on the X-E1 and I was really trying to see how it did versus the rest of the cameras. That said, the X-E1 is slow slow slow, it might get the shot in focus, but you have quite a delay. The PM2 and RX100 are lightning quick, almost feel faster than the D5100.
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  2. mattia

    mattia Mu-43 Hall of Famer

    May 3, 2012
    The Netherlands
    The RX100 has the added advantage of a smaller sensor with a wide lens, so more depth of field. It helps. Great little camera though :)
  3. yakky

    yakky Mu-43 Top Veteran

    Jul 1, 2013
    It does indeed but so does the X10. The X10 is so bad in comparison. That said I was using carpet as a reference point for the focus zone and if the target wasn't smack dab in the center I counted that as a near hit which wasn't factored into the above.
  4. Bokeaji

    Bokeaji Gonzo's Dad O.*

    Aug 6, 2011
    Austin, TX
    oh man, i wish you had used a fast focussing lens on the oly! i bet it would be in the high 90s! :D
    • Like Like x 1
  5. Ulfric M Douglas

    Ulfric M Douglas Mu-43 Hall of Famer

    Mar 6, 2010
    Thanks for the test : and using the Lumix 20mm!
    Good results, and what would the 17mmF1.8 have done?
  6. mfj197

    mfj197 Mu-43 Regular

    Aug 20, 2012
    Guildford, UK
    Real Name:
    I used a similar technique when taking some shots of a dance at a wedding. It was a folk dance and at the end of each musical repetition a couple would dance / hop / jump at high speed from one end to the other in between all the other dancers. I was standing at the end using the Oly 45 on a Panasonic G3 as the couples bounded straight towards me. I had a very high hit ratio - worked fine!

    Incidentally the Panny 20 isn't the best for this technique, but not because of its slower focusing speed. Assuming yakky set the PM2 to only fire once the object was in focus it doesn't actually matter how long the lens takes to get to being in focus - the camera won't fire until it is. The P20 isn't the best because it also has quite a slow operating aperture, so the object may move out of the focal plane whilst the aperture mechanism is closing for the shot. Of course yakky got around this by using the lens wide open. If you stop the P20 down to say F4.5 the max frame rate on my E-M5 drops from over 8fps to under 5fps.


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  7. broody

    broody Mu-43 Veteran

    Sep 8, 2013
    It's been measured; it focuses about 3 times faster if I recall.