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How to deal with minor jello? (video inside)

Discussion in 'Pro/Adv Discussion' started by Quafe, Aug 1, 2015.

  1. Quafe

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    I've finally taken my P3P outside and flew it over some small islands in Norway. Stream was rock-solid, and all video settings were default 4K. I also have not calibrated the compass since I wasn't very far from my home. Anyway, I've noticed that there is some minor jello in the video. What's the best way to deal with it?

     
  2. taroh

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    ND filter. Changes jello into blur, however much better. I use ND8 when over Ev 12.
     
  3. Quafe

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    I considered it, but it would not remove the underlying issue.

    The gimbal itself is very stable, so my next guess would be minor imbalance in props. Or is there something else which can cause this subtle jello?
     
  4. taroh

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    Basically I agree, I hate ND to remove jello. But vibrations from motor (50-200Hz) cannot be removed by dumper nor gimbal perfectly. As you said, perfect balance of props may improve this, but have production error, maybe damaged even while flying, and wind conditions... And any post-processing software can remove jello. ND filter is my compromise after few years trial. :) until Phantom 4 camera equips global shutter imager.
     
  5. zryall3

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    What exactly is "jello?" I see it discussed and assume it is some minor vibration in your video even after dampening, but is it caused by something in particular or shows up in particular circumstances?
     
  6. taroh

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    For exact definitions, please refer to Wikipedia: https://en.wikipedia.org/wiki/Rolling_shutter .
    Cameras which have rolling shutter is vibrated and shutter speed is few times faster than frame rate and vibration frequency is few times of frame rate, whole footage vibrates like jello.
     
  7. zryall3

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    Thanks, that was helpful. So that rule of thumb about shutter speed twice the frame rate is partially designed to minimize jello? That's where the ND filters come in?
     
  8. taroh

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    Right. Since we cannot control brightness of the sun, ND filter works. I personally allow shutter speed = x1 .. x5 times of frame rate.
    Actually ND filter turns jello into blur, so sharpness of the image will lower... I hate that.