Video light changes

Discussion in 'Olympus Cameras' started by EM5 Learner, Apr 14, 2015.

  1. EM5 Learner

    EM5 Learner New to Mu-43

    4
    Apr 14, 2015
    Craig Benbow
    When taking video the light intensity changes as the lens refocuses and adjusts. Is there a setting or a way to set up for video that smooths the transitions or reduces them?
     
  2. dornblaser

    dornblaser Mu-43 Hall of Famer

    Aug 13, 2012
    Chicago-area
    David Dornblaser
    Are you using AF?
     
  3. EM5 Learner

    EM5 Learner New to Mu-43

    4
    Apr 14, 2015
    Craig Benbow
    Yes. I was surprised how much the picture changes. Of course I was recording relatively fast moving objects so I guess that doesn't help. I set the focus area to the centre of the picture and to only one square. What more can I do?
    I've thrown together a video, you can see what I mean in it.
     
  4. dornblaser

    dornblaser Mu-43 Hall of Famer

    Aug 13, 2012
    Chicago-area
    David Dornblaser
    Switch off AF and try shooting again. There is a reason that documentary and indie producers use rigs and sliders in order to shoot in MF.

    Post-Script: very cool subject material! The one thing that jumps out at me, no pun intended, is that some of video is jumpy and that you are reacting to your subject(s) rather than anticipating their movements. That said, I will let some of the real videos experts take it from here.
     
    Last edited: Apr 14, 2015
  5. EM5 Learner

    EM5 Learner New to Mu-43

    4
    Apr 14, 2015
    Craig Benbow
    Thanks, is there a shortcut to turn it off? Still trying to get to grips with this camera and yep, planes coming at you at 350mph or more is a bit hard to follow. As an amateur I don't have clear views unless I get right to the fence and that makes it even harder to follow the action. I will keep your comments in mind though and try to be a bit better prepared before the next event.
     
  6. ApGfoo

    ApGfoo Mu-43 Regular

    158
    Dec 10, 2012
    Bay Area
    Assuming, shutter and and aperture settings stay the same, auto ISO might slowly try to get the right exposure, hence the flickering.

    Also, I don't have any experience with zoom lenses when shooting video on micro four thirds but try shooting at an aperture that stays constant. that might also affect exposure with flickering if the aperture changes while recording.
     
    Last edited: Apr 15, 2015
  7. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    Does it happen if you use manual exposure or "auto exposure lock"? Supposing these are available for video too.

    It could be just the different amount of sky present in the framing that force the camera to correct the exposure. I'm speculating, not a video expert.
     
  8. DaveEP

    DaveEP Mu-43 Top Veteran

    684
    Sep 20, 2014
    York, UK
    AF/ MF have nothing to do with exposure changes, they are strictly focusing issues.

    You need to be locking Aperture / Iris, Shutter Speed and ISO/Gain. With all these three locked the in-camera exposure will remain the same regardless of where you point the camera. Of course, if you point it in a dark hole and then at the bright sky that may not be what you want, but in those cases you should probably be editing them between different shots.

    99.9% of everything we shoot for video is on manual exposure. We'll use AF maybe 5% of the time at most.
     
  9. EM5 Learner

    EM5 Learner New to Mu-43

    4
    Apr 14, 2015
    Craig Benbow
    Ahh yes that is turned on. I'll do some testing to see what works best but auto ISO could well be the problem. Trying to come to terms with what the camera is actually doing is a bit difficult. There is no record of the aperture when recording but it could be changing. So if it was set to AP I wonder what would happen......
     
  10. PowerHawk2015

    PowerHawk2015 Mu-43 Regular

    35
    Mar 8, 2015
    Australia
    In aperture priority, the aperture will remain constant ?(until you manually change it) while the shutter speed fluctuates, you generally want the shutter speed to be fps x 2 when recording video.
    In shutter priority, it's the opposite. Having the aperture fluctuate (while SS is constant) during changes of lighting will render a smooth transition between lighting changes, it should appear seamless.
    Use iso to fine tune where you want the aperture to hover, and EC to adjust lighting in your scene.
     
    Last edited: Apr 15, 2015