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Focus searching?

Discussion in 'Filmmaking' started by salvatore64, Aug 12, 2013.

  1. salvatore64

    salvatore64 Mu-43 Rookie

    23
    Jul 17, 2013
    That's the best way I can describe it. When ever I do video with my OMD no matter the lense the camera always loses focus on and off and focuses on different subjects during video. What am I doing wrong? Is their a secret setting to avoid this ?
     
  2. Lobbamobba

    Lobbamobba Mu-43 Veteran

    388
    May 15, 2013
    Sweden
    There is, manual focus, sorry but thats the only way to get it right.
     
  3. salvatore64

    salvatore64 Mu-43 Rookie

    23
    Jul 17, 2013
    When using MF, will it track a subject? For example someone walking around singing on stage?
     
  4. Lobbamobba

    Lobbamobba Mu-43 Veteran

    388
    May 15, 2013
    Sweden
    Nope, thats your job.
     
  5. umii

    umii Mu-43 Regular

    50
    Aug 19, 2013
    uk
    Depends what you are doing but say it's on stage with multiple people moving I use a depth of field calculator on my phone and work out a virtual box in my head that the subject can move about it and manually focus on a point in the middle of that box so for example

    35mm lens on a GH3 at f5 focused 10m away the subject can move back 15.97m and forward 3.81m and be in apparent focus.

    Becomes tricky if the lighting gets low as you'll have less room mainly in front of the focus point when the lens is more open. Just experiment video is much more forgiving than stills for focus.

    For auto focus I can only comment on the GH3 but I guess it crosses over, check the lens specifications some have faster auto focus than others, I change the focus to centre weighted and keep that quite small so I have better control over where it is focusing. keep f stop up to give you a bit more room for error. I rarely get any hunting etc. doing it like that.

    Another trick I use a lot is do the half press to get the auto focus to kick in, flip it over to manual focus or press the lock button to lock that focus then start recording, that's pretty much second nature for me now with more static shots.

    I posted this example in another thread but it's f18 centre weighted for focus continuous auto focus and zooming in and out, tracks it pretty well. gets trickier if it's low light, i'd go manual and the previous technique if there was a lot of movement in low light (45-175mm Lumix G x iso200 25fps 1/50)
    [ame=https://www.youtube.com/watch?v=J96eDuH_U4o]Pip day 129 19/08/2013 - YouTube[/ame]

    This is f2.8 terrible lighting same setup with someone who has never held the camera before with instructions to keep me in the middle and point and shoot with the 12-35mm iso400 25fps 1/50 keeps focus pretty well. thats with the latest firmware in the lenses and camera which have low light improvements for focus.

    [ame=https://www.youtube.com/watch?v=hY-NJIYWj2Y]pip day 127 17/08/2013 - YouTube[/ame]

    This is f5.6 iso800 manualy focused on the middle jump only no auto focus
    [ame=https://www.youtube.com/watch?v=OKx1-O4uMTo]Westly Jumping Jan 2013 - YouTube[/ame]

    you have to play about lots :)