• Apple Final Cut Pro Legacy

  Video Pulsing Problem

  Posted by Brian Maynard on May 27, 2009 at 10:13 pm

  Hi,
  I am still a rookie and searched for a similar problem, but didn’t see anything so I thought that I would ask.

  I videotaped an event last weekend with two Canon XH A1 cameras. I taped in 3 different locations. After capturing the video to my computer, the video from the first two locations looks fine, but the video shot in the last location has a slight “pulse” every 1/2 second or so where the brightness and color changes very slightly. I can see it on the Canvas and on the Waveform scope.

  Any ideas what is causing it. It was taped in 1080i60 at 29.97. First I thought that the problem was caused because the sequence was set to anamorphic DV, but when I viewed it in HDV, it had the same problem. It is not real noticable, but I noticed it. Is it a lighting issue?

  Thanks in advance for any help.

  Brian

  Brian Maynard replied 16 years, 11 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Tom Matthies

  May 27, 2009 at 11:44 pm

  Did you shoot under florescent or mercury lighting by chance. I’ve had instances where I get the same effect that you are describing except that the pulsation is much longer. I would usually notice it while scrubbing through a scene at high speed. Some lighting fixtures will change their output very slightly when running on AC power, especially the high voltage units used in larger installations. Usually the pulsations are so slow, tied to the frequency of the lower grid, that it’s difficult to notice them. If yours are faster, it might be something different.
  Did this camera have a shutter speed different than the other cameras? That can cause the same effect as well.
  Just a few thoughts.
  Tom
• 

  Brian Maynard

  May 28, 2009 at 12:11 am

  Hi Tom,
  thanks for taking the time to try to help.

  The lights that I could see looked like they were incandescent, but there were other lights that were hidden and aimed at the ceiling, so I couldn’t see what they were.

  I agree with you, though, that it must be some kind of lighting or electrical issue, because I didn’t see the problem at the other location with the same cameras, but both cameras exhibit the same issue at the one location.

  When I look at my properties, it says that the frame rate is 29.97, but it was shot at 60 fps…? Hmmmmmmm

  Any ideas on a way to correct?

  Brian

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