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  1. David Cooke

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    I've noticed some "twitching" in my videos . . just a very quick step like it misses a frame or two. . .but more importantly there is obvious banding sometimes that can ruin a shot completely. Does any one know the cause? Is it just because I'm shooting into the sun and the AWB (Automatic White Balance) can't decide what to do?
    Thanks for any ideas . . check this short video clip especially in the top right of the frame.

    Video removed as unnecessary. The banding is Blade Shadow.
     
    #1 David Cooke, Oct 13, 2016
    Last edited: Oct 13, 2016
  2. msinger

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    The banding is what is commonly called prop shadows. You should be able to eliminate that issue by using ND filters or flying with the sun behind the Phantom.
     
  3. David Cooke

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    You really think so . . I've seen prop shadows but nothing as regular and even as that . . the prop shadows I've seen are sweeps across the frame that are tapered as the prop passes the frame . . . not parallel bands. This seems to come from the sensor itself because the bands are perfectly parallel and regular.
     
  4. msinger

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    To clarify, I was referring to this:

    Bands.png
     
  5. David Cooke

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    Yes exactly, that is what I'm referring too as well. But these bands seem to parallel and regular to be caused by the props. . . is it possible it is just the shadow of the props that causes this in harsh light? Is that what you are saying? . . if so then thanks for that confirmation . . back to my other question then where does the video "twitch" come from . . every once in a while it seems to skip a frame or two and I've only noticed this since v3.0 software upgrade.
    Thanks . . I appreciate your perspective
     
  6. Javiejav

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    Prop shadows. Exactly what it is. I got caught with them too when flying out over Sedona...




    Sent from my iPhone using PhantomPilots
     
  7. David Cooke

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    Yes I see . . exactly as msinger said . . and I see it in yours now when you were shooting into the sun. Hopefully Mavic will avoid that with the forward camera mount. Can anyone tell me why the Camera TWITCH is happening since I upgrade to v3.0 . . Looks to me like it's dropping frames randomly or maybe a gimbal fault. This is a 10 acre maze carved out a corn field.

    Watch at the point of the laser gun sounds. I did this intentionally to preserve the shot and make it look intentional. The camera twitch was not intentional and the shot was otherwise ruined by the twitches.

     
    #7 David Cooke, Oct 13, 2016
    Last edited: Oct 13, 2016
  8. John Locke

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    Just to be clear, you're saying the SD card video is dropping frames? What resolution and frame rate are you shooting to you see this anomaly?
     
  9. David Cooke

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    It seems that "something" was dropping frames. Could it be the processor or the software as it sends them to the SD. This is what I got off the SD. Premiere Pro reports the input file as 1920x1080p at 29.97fps.

    If I carefully pan back and forth through each frame it seems there are no missing frames. I appears that part of one frame is being mixed with part of the subsequent frame. You can see between two adjacent frames that the center of the field of view is progressing smoothly while the upper part of the frame is from the next frame and has been mixed with this one. It's like halfway through storing one frame it overwrites part of the data with the next. The upper 1/3 of that frame is what should be on the next frame and one frame later it catches up and the whole frame is back in sync.
     
    #9 David Cooke, Oct 14, 2016
    Last edited: Oct 14, 2016
  10. JCP10

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    Thank you for this post. I just got this same banding effect today on my P4 on a bright sunny winter day....and I had never seen it before. This in addition to a couple of other annoying small problems while flying FPV made me wonder what was going on overall, and I began to get a bit concerned. Signal strength also seemed very low today, even using range extenders...it was frustrating because it's been the first nice day in weeks.
     
  11. David Cooke

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    It's just the blade SHADOWS passing across the lens when you look toward the sun or bright sky . . does not happen looking "down sun"
     
  12. rocketflyer

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    Go app v3.0? Seems strange that the app can cause this to happen.

    Have you tried it with Go 4? (which you will soon have to anyway, as the P4 will soon no longer be supported in the 'normal' Go app) Or reinstall an older version from your phone/tablet backup if you have one.
     
  13. David Cooke

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    I have a P4P+ and Mavic now and neither show these issues but I have not specifically been able to test them since its been overcast or rail or snow for weeks here in Sarnia . . I use DJI GO 4 on both as well as Litchi on the Mavic
     
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