E-PM1 focusing issues

Discussion in 'Olympus Cameras' started by dhazeghi, Jun 23, 2012.

  1. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Dara
    There are a couple of things that are starting to bug me about the E-PM1's focusing. I was wondering if anybody knows of workarounds for these, or whether the new E-M5 does a better job.

    1) The focusing box cannot be set to small permanently (changes are lost when the camera is powered off).
    2) Setting to the focus box to small blocks other functions. You cannot have it display the live histogram (or any other useful info. beyond shutter speed and aperture). You also cannot access the Super Control Panel.
    3) In poor light AF hunts and frequently gives up. With the mZD 45/1.8 in a dim but not absolutely dark restaurant (f/1.8, 3200, 1/80s), even with a high contrast target it failed to lock on focus an average of 4 out of 5 times. I wouldn't mind if it were slower in low light, but failure to lock at all is annoying.
    4) The CDAF algorithm is easily fooled at near focusing distances. With both the PL 45/2.8 and the ZD 12-60, AF past about 1:6 magnification is very hit-or-miss. It not infrequently confirms when absolutely nothing is in focus.
    5) For manual focusing, there is no way to frame and focus without jumping in and out of magnified view (unlike, say, the Panasonics).

    To be clear, on the whole the camera focuses well, but there do seem to be a fair number of situations where things aren't quite so rosy.

    Thanks,

    DH
     
  2. b_rubenstein

    b_rubenstein Mu-43 All-Pro

    Mar 20, 2012
    Melbourne, FL
    I doubt that its the CDAF algorithm that is the root cause of the AF problems in low light. The universe is not a software app, and in this case the case is probably due to the fact that large aperture, longish focal length lenses have very soft out of focus areas that don't provide enough contrast to focus on.

    I have the same problems with an E-PL2 with primes, but has very little problem with the 14-42 kit lens.
     
  3. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Dara
    But apparently that's still more than enough information for a PDAF system to focus on, as my friend and his Canon have now proven several times. Considering how much older his camera is, that's hardly a recommendation on progress.

    DH
     
  4. atomic

    atomic Mu-43 Veteran

    224
    Nov 3, 2011
    Unless your friend with the canon is using the exact same lens that would not be a fair comparison. As to your original query, go into the custon settings gear menu and turn manual focus assist off. Then it won't zoom every time you try to focus a native lens. Then set the video button to the magnifying glass in the button menu. Then clicking the video button once frames the focus preview, the second press magnifies and the third returns the camera to normal.
     
  5. alan1972

    alan1972 Mu-43 Top Veteran

    592
    Jun 23, 2012
    Malaga, Spain
    Alan Grant
    I don't seem to have problems (1) and (2) with my E-PM1. Maybe you are using the focus box in a different way to me, or maybe I have misunderstood what you are referring to.

    I'll describe my steps in detail to make sure we are talking about the same thing. Suppose I start off using the "big box" for autofocus, i.e. all 35 focus targets are active.
    Press the left button on the wheel to bring up the focus target grid, showing all 35 boxes illuminated.
    Press Info and scroll down to choose the single focus target. Now just one box in the centre of the screen is illuminated.
    Press Info again and use the arrows to move the box to the left of centre (I would more likely leave it in the centre, but just for the sake of illustration).
    Press OK or half-press the shutter to return to the normal shooting display. The chosen focus box is indicated on the screen by outlined corners.
    I can now use Info as normal to cycle through the usual displays (histogram, shadow/highlight and so on). I can also use the Super Control Panel as normal. The fact that the small focus box is now in use doesn't restrict anything.
    Power off the camera.
    Power on the camera.
    The focus target shows up as a small box to the left of centre - i.e. both the size and location have been retained during power off.

    I can't say much about (3) as I don't have the 45mm lens. I find the Panasonic 20mm lens sometimes takes its time to focus in dim light but so far it hasn't failed to lock. But I have not had it very long and obviously it's a completely different lens so may not be relevant anyway. Do you have the "AF illuminator" set to on or off?
     
  6. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Dara
    Well the current generation Pens until a few months ago were supposed to have the top AF system (at least for S-AF) in m4/3 land, and the 45/1.8 is widely considered among the best focusing m4/3 lenses, so comparing a 3 year old Canon and an equally old (and not particularly fancy) lens seem fairly reasonable.

    More to the point, he got his shots. I didn't. The latter point is what I find annoying.

    That's how I have it set up. I don't ever zoom with a native lens - only with MF lenses. But the point is that for those I cannot both frame and focus - I have to switch the view back in forth. Panasonic and probably others have a very simple solution - a mode where the magnified view is overlaid in the center of the frame.

    Thanks,

    DH
     
  7. BarefootPilgrim

    BarefootPilgrim Mu-43 Top Veteran

    517
    Dec 23, 2009
    Westchester, IL
    Bob
    Huh????

    I keep seeing people say this, but that's not my experience at all. With my G2, it's simple to switch to MF assist magnification, but the entire frame shows that magnification, not an area "overlaid in the center of the frame."

    Am I missing something in the camera settings that would make this happen?

    I'll grant that Panny has made switching to MF magnification much simpler than Olympus has, and that's one reason I love my G2. But my G2 still shows that magnification across the entire screen, not in a box overlaid in the center of the frame. Therefore, I have to switch it off in order to frame my shot properly. (Doesn't matter what lens is on the camera, m4/3, 4/3 with adapter or adapted legacy MF lens, the camera shows the same full-frame-of-the-viewfinder/LCD display magnified thing with all of 'em.)

    Does anyone know how to make the magnification "overlaid in the center of the frame?" Or is that another of those internet myths perpetuated by the grossly uninformed?
     
  8. dhazeghi

    dhazeghi Mu-43 Hall of Famer

    Aug 6, 2010
    San Jose, CA
    Dara
    The 'big box' I'm talking about is one of the 35 to begin with. If you hit the magnify button twice, rotate the wheel to zoom to 14x, then hit the magnify button again, you'll see the AF box has shrunk a lot more.

    I've tried both on and off. It makes surprisingly little difference.

    I believe it's something they added to the G3 and newer models.

    Thanks,

    DH
     
  9. atomic

    atomic Mu-43 Veteran

    224
    Nov 3, 2011
    Ok, I guess I misunderstood. I do not know of a way to do thid without switching. However, after a little practice, I don't find switching to be much of a problem.
     
  10. Mookalafalas

    Mookalafalas Mu-43 Veteran

    369
    Feb 22, 2012
    Tainan, Taiwan
    Al
    I have the focus problem a LOT when I am focusing on something in the foreground. The box will lock right on my target, and the E-PM1 "beeps" that it's in focus, but it's not just "a bit" out of focus, it's not even close--the far distant background will be in focus and the foreground object is just a blob. Generally I have to move the camera back while continuing to hit the shutter button until it finally comes into focus, and then move back up again and hope it stays that way. Very irritating.
     
  11. demiro

    demiro Mu-43 Hall of Famer

    Nov 7, 2010
    I find my E-PM1 to focus very quickly with both the 45/1.8 and 14/2.5.

    I do sometimes experience something similar to what Mookalafalas is mentioning though. Seems like when I am close to minimum focus distance I occasionally get the beep and green box, even though subject is out of focus. It seems that the next object moving away from the camera is in focus, not something in the distance.

    Not a big deal for me. Usually pulling back just a bit solves the problem.