Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Professional Pulsing/flickering video (even with auto WB off)

Discussion in 'Phantom 3 Help' started by Trumple, Jun 9, 2015.

  1. Trumple

    Joined:
    May 19, 2015
    Messages:
    279
    Likes Received:
    73
    Location:
    UK
    Hi all,

    A little while ago I posted a thread asking for some help with recorded video flickering or "pulsing". Here's the original video:



    It was suggested that I turn off auto white-balance, which I did (I turned it to "sunny" mode - as far as I know, this is not an automatic mode either, but I could be wrong?). I thought it helped, but I discovered the same effect in later videos.

    I also tried using advanced camera settings mode to try to override any automatic settings that might be jumping around. You can see me fiddling around with the advanced settings below, and yet the video still flickers in-between settings changes:


    It's a little hard to see in the video above, but it's very obvious in the raw footage.

    It really ruins the shots so I'm a little disheartened now that I might have to send the aircraft back :(

    I've noticed something though: the EV value seems to jump around by itself depending on the lighting conditions in advanced mode. I thought the EV was based on the aperture (fixed in this camera) and the shutter speed, so why is it jumping around? Could that explain this effect?

    Side note: how do I get longer exposure values? It seems I'm limited to fractions of a second rather than being able to go up to whole seconds.

    Thank you for any help. I'm a total camera noob so please feel free to suggest things which might seem blindingly obvious to you. Please note that this effect happens in the raw footage too, so we can't blame YouTube.
     
    Ari likes this.
  2. dhaslam

    Joined:
    Apr 8, 2015
    Messages:
    73
    Likes Received:
    9
    I wonder if it could be a shutter problem. CMOS sensors seem to emulate focal plane shutters in software by sensitizing part of the image in sequence. It wouldn't take much of a fault to upset the final image.

    http://en.wikipedia.org/wiki/Rolling_shutter
     
  3. sergekouper

    Joined:
    Apr 20, 2014
    Messages:
    752
    Likes Received:
    128
    Location:
    London UK
    This is not flickering. A flickering picture vibrates at the speed of the power frequency. You have a bit of jello for sure and compression artefacts. Your video codec or/and the post treatment tend to produce these on relatively uniform patches of color. Check your export settings. shoot a different kind of background to compare.
     
  4. Trumple

    Joined:
    May 19, 2015
    Messages:
    279
    Likes Received:
    73
    Location:
    UK
    Sorry - I realize it's not the flickering associated with artificial light, but I didn't know how else to describe it (perhaps "pulsing" is a better word)
    I think exporting magnified the problem, looking back on the raw footage, but it is still there in the raw footage. Shooting a plain background such as a car park does indeed solve the "pulsing" problem. This ties in with what you are saying. I'm fairly confident the camera itself is not faulty now, and it's just a limitation of the hardware.

    Thanks for the responses
     
  5. Jwffvm

    Joined:
    Jan 20, 2014
    Messages:
    7
    Likes Received:
    0
    We have the same "pulsing" going on in 4K. Haven't tried 1080p, since all I shoot in is 4K. It's a significant problem showing up on my waveform monitor with the waveform jumping up and down as much as 10 IRE. Totally unusable without adding a Digital Anarchy flicker filter to the shot, which take a long time to render and I have a very fast system and Raid, viewing on 27" IMAC Retina 5K and an Asus 4K monitor.

    This occurred on manual Iris and white balance set to sunshine, using both an ND32 and ND 16 filter. I'm going to shoot a test today with the 3D noise reduction filter off though I'm not holding much hope that is the problem or solution. I do have an HDMI Module connected to my RC so I'll also shoot a test with it disconnected and the stock USB box installed.

    thx...jw
     
  6. Chad Nickle

    Joined:
    May 29, 2016
    Messages:
    3
    Likes Received:
    0
    Did anybody ever figure out what the heck is going on here? We are heaving the same problem and its infuriating. Doesn't do it in 1080p or 2.7k seems like grass and trees really make it worse.
     
  7. martin974

    Joined:
    Jun 30, 2016
    Messages:
    9
    Likes Received:
    1
    Same issue here, actually doing an edit comparing all footage, intensive test. But when uploaded to youtube, the compression made those artifact less visible...stay tune I'll post it via dropbox for Hi Res file.
    But to sum up, yes 4k is awful, flickering and pulsing, 2k and HD are great.