"Banding" Issue When Shooting Laser Show Videos

Discussion in 'Lasershow Designer BEYOND' started by base851, Jul 29, 2017.

  1. base851

    base851 Member

    This isn't necessarily a Beyond-specific question, though I am using Beyond Professional to control my projectors.

    I'm in the process of making some demo videos in my studio and having problems eliminating a "banding" phenomenon... I can get nice, clean, sharp video between 24-30 fps, but I'm seeing a pattern of dark bands crossing the screen diagonally at regular intervals. I've tried all kinds of iris, shutter & gain settings to deal with it, but the settings which provide the best quality video also have the problem most noticeably.

    I'm assuming there's some sort of synchronization issue going on between the camera's shutter/iris settings and the frame rate coming out of the projector. I just can't seem to get the two to line up.

    My camera is a Sony PXWZ150, so I know camera quality isn't the issue, just a settings issue. I generally shoot full manual... full auto looks awful.

    For those of you with experience recording video of laser shows... especially if you're using Beyond... can you offer some tips for how to resolve this sort of problem? Is there something I can do on the Beyond side to sync up with the camera, or vice-versa?

    Any suggestions would be appreciated! :)
     
  2. base851

    base851 Member

    I did some experimenting today. I was able to mitigate it fairly significantly by making adjustments to the scanner and animation speeds, but not remove it completely.
     
  3. lorenzopompei

    lorenzopompei Active Member

    I saw the same problem, but not even with professional cameras we got the problem, it slows down by changing the scan rate, but it should be adapted for each animation
     
  4. base851

    base851 Member

    Yeah that's basically what I wound up doing... pick a camera frame rate that I thought attainable by all of my cues and set the scan rate accordingly (by tracking the FPS at the bottom right of the screen) on a cue-by-cue basis. What I found though, was that within a given cue, despite a concrete scan rate, FPS often fluctuated depending upon the load on the projector.

    I was beginning to think it was just me until more looking around found that the "mismatched frame rate" problem is a fairly common (and insanity inducing) thing when taking video of laser shows.

    In fact, now that I sort of have an eye for it, I noticed even the placing ILDA videos had it, though they either matched the rates better or had a good debanding plugin in their video software.
     
  5. base851

    base851 Member

    Does anyone know if Beyond has an option to lock scan rates to frame rates (or vice-versa)? Sort of like toggling maintain aspect ratio when resizing something in a graphics program.
     

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