Olympus E5: 11-point TTL Phase Difference Detection

Discussion in 'Digital Photography' started by Peter Jason, Jan 4, 2013.

  1. Peter Jason

    Peter Jason Guest

    When I photograph a group of people, say 12, how
    does the "11 point focus" know where to focus?
    Does it go for the movement or does it average the
    lot? There's no explanation in the manual.

    Some cameras have far more than 11 "point focus
    points".

    Peter
     
    Peter Jason, Jan 4, 2013
    #1
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  2. Peter Jason

    RichA Guest

    How does 49 points know? How does 51? They don't. Which is why
    letting the camera do the choosing, even when it averages them, is
    often off the mark, especially with scenes with multiple DOF objects.
     
    RichA, Jan 5, 2013
    #2
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  3. Peter Jason

    DanP Guest

    You'd be very lucky to have all focus points covering your subject(s).
    Some will be sitting over the background.
    It has to be a clever algorithm trying to guess what you want to do.

    I only use the central focus point, half press and recompose the frame.
    That way I get to focus where I decide. If I want to focus over a wider range I close the aperture. No guessing involved.

    I don't like to use tools smarter than me, make me look stupid and not knowing what I am doing.


    DanP
     
    DanP, Jan 5, 2013
    #3
  4. Peter Jason

    Peter Guest

    For that type of shot I do not use autofocus! Instead I try to set a
    hyper-focal distance, with an appropriate f stop. the problem is that
    many of the ewer lenses, don't have the hyper-focal distance on the
    barrel. In that case I apply "Kentucky windage."
     
    Peter, Jan 5, 2013
    #4
  5. Peter Jason

    Peter Jason Guest


    I have set the camera with a 600mm (4/3) lens on a
    tripod in a room that overlooks the coffee shop
    over the road about 25 meters away. The denizens
    there sit at tables on the footpath/sidewalk
    sipping lattes. The tables are randomly situated.
    The camera fires once every 15 minutes. The
    F-stop is 8.0 on aperture mode.

    At the end of the day I check the photos and
    discover the focus point varies randomly and there
    seems no reason for this. Sometimes it focuses
    on a lamp post and other times on a chair back and
    sometimes on a subject.

    Curious
     
    Peter Jason, Jan 6, 2013
    #5
  6. Peter Jason

    Mort Guest


    That's the way to go.I have been doing that for many years, after
    getting tired of blurred faces and a sharp wall way behind the faces.

    Mort Linder
     
    Mort, Jan 6, 2013
    #6
  7. Nope. In most cases "closest distance" works very well: few
    people shoot through fences or bushes or leafes to capture
    the subject. Those that do know how to tell the camera which
    focus point/points/point groups to consider.

    However, today face detection can be an even better solution
    when a face can be found, as most people want the faces sharp.

    And the larger the recompose angle, the more the recompose moves
    the focus behind where you want it to be. Doesn't matter a
    lot with tele lenses (small recompose angle) or when you have
    much DOF.

    I love the capability of the 5D3 to memorize a different
    focus point (or group) for both portrait and landscape ---
    thus I can offset it so I don't need to recompose much when
    I'm photographing similar situations in a row in both
    orientations. Like people on a stage ...

    It's quite easier than central focus point only ... which I
    used to do for many years.

    You *could* learn more about the tool --- it's not THAT smart.
    Or you could switch to manual focus and manual mode.

    -Wolfgang
     
    Wolfgang Weisselberg, Jan 10, 2013
    #7
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