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Help with diagnostic of video problem

Discussion in 'Pro/Adv Discussion' started by JayB, May 22, 2015.

  1. JayB

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    Hi

    I posted some footage last week that showed the image flicker slightly and then go from a bluish green to a bright yellowy green. Most of the comments revolved around not using the auto settings so that's what I tried. the first time I took it out using manual settings things were a lot better, however I took it out tonight and it was worse than ever, I still had WB, ISO and shutter all set in manual mode and colour was set to log, I also know how to keep it in manual rather than auto, but looking at how quick and random some of the flicker is I think it would be difficult to replicate. The only difference seemed to be that tonight there was more wind and it had to work a little harder to keep its position and im wondering if somehow the power to the motors is interfering with the camera.

    I have watched a lot of videos on this forum from the P3 and whilst some do show slight signs of various artifacts I have seen none as bad as this. Any other ideas of what I can try to at least pinpoint what could be causing the problem or better still stop it altogether before I have to send it back to Heliguy......gutted if I have to do that.......:(

    The footage was shot in 1080p 50fps but I rendered it as 720p 30fps to upload, the footage looks identical to playing it straight off the SD card.

     
  2. Kingfish28

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    Looks like it got tired of your underexposed video and decided to help you out.



    ;)
     
    sergekouper likes this.
  3. JayB

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    If only it was intelligent enough to have an opinion............ maybe it has....... maybe Kingfisher28 is just your alias and in fact you are the AI of the P3 let loose on the interweb to ridicule us mere humans in how crap most of what we do looks crap... Cheers...;)
     
  4. Kingfish28

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    Anything is possible.
     
  5. sergekouper

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    It looks like you have a manual control on the exposure and you use it by accident. I don't have a p3 so I can't speak much about it, but if you can control the camera in flight, that could be a lead...
    on another subject, what are you calling a flicker? I don't see any flicker effect on your video.
    Also, I noted that you shot at 50 fps and render at 30. 30fps is used in the US basically because their power is oscillating at 60 Hz. in the UK we are at 50hz and our frame rate is 25. you should then render at 25. or your might face missing frames during the render.
     
  6. JayB

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    Definitely not changing anything in manual mode, I have 16 minutes of video that shows signs of what I call flicker, where it will go from light to dark and back again in quick succession. admittedly the sample posted doesn't really show this and shows what appears to be the exposure stepping down and then up. I tried to render some more footage with the flicker but after rendering its almost impossible to see. I did play the footage straight off the card and my partner could also see the flicker so I know its not just me going mad.
    Thanks for the tips on rendering the video, I am new to this and whilst I understand the difference between PAL, NTSC, 50Hz & 60Hz I didn't even think about rendering in lower frame rates, I chose 30 because I'm sure that I read that's what Vimeo prefer and I was going to set up an account with them.
    I have now updated the firmware and am going to try a new SD card and play the footage back on a different computer just to make sure its not just my set up. I have seen links on here so members can upload the raw footage, that would be a great help but I have no clue how to set that up.

    I really don't want to send my bird back, thanks for your input.
     
  7. dhaslam

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    It seems to be like photographing a black cat against a white fence or vice versa. In this case the black trampoline against the lighter green grass is making the adjustments based on the overall average and when you go a little closer to the trampoline the exposure increases. That implies that the meter was still in control of exposure and that could happen if you exited manual control via the screen icon or one of the switches on the bottom of the controller.
     
  8. 4wd

    4wd

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    Just to confirm; when you make your manual exposure adjustment it will revert to auto if you tap the slider icon to make it disappear.
    To stay in manual mode swipe the window back to the left side.
    You can then still manually adjust shutter or ISO with the right wheel.
    Pressing the wheel in changes between the two, and the adjustment which is active is shown blue near the top right of the screen
     
  9. JayB

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    Thanks 4wd but I do already know this, you can tell its still in manual mode because after you have swiped to the left there is a small icon with a lock on it in between the auto takeoff/land and the home icon.
    I'm just about to go back out into the yard to see if the update or new HD card has made a difference, I will be extra vigilant to make sure 100% that it stays in manual mode and that I do no inadvertently catch the dial to change any settings...... fingers crossed.
     
  10. JayB

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    :)....... I don't know whether its the firmware update or new SD card but I just shot 16 minutes of my daughter on the trampoline again, I took it up to 400 ft did a few 360's and the picture was as solid as a rock, not one teeny weeny hint of a flicker or change in colour balance or change in exposure. at certain points I changed this manually to avoid the dreaded overexposure hatching, but apart from that it was brilliant..... I am one very happy man.... :)

    Now I'm even more excited about getting my ND filters from Data.