• Media 100

  Field Dominance

  Posted by David Issko on October 8, 2008 at 3:31 am

  Hi,

  I have some lower field first qt movies that play back very jittery in M100. Obviously wrong field dominance. I have solved this issue before but I cannot remember what I did. AE field change possibly.

  Anyone able to let me know the quickest solution?

  Thanks
  David Issko

  David Issko replied 17 years, 7 months ago 3 Members · 7 Replies
• 7 Replies

• 

  Wickham Strub

  October 8, 2008 at 11:18 am

  Without knowing any of the details, one quick trick that comes to mind is putting the file into an AE comp and moving it up or down one line. As long as you render out to the same codec and settings, this should have the effect of swapping the field order.
• 

  David Issko

  October 8, 2008 at 8:50 pm

  Thanks Wick,

  I’m sure that other operators must have come across this problem as well. Anyway, I might just try that trick on a known piece of ‘strobing’ video.

  Thanks again
  David Issko
• 

  Floh Peters

  October 8, 2008 at 9:26 pm

  [Wickham Strub] “Without knowing any of the details, one quick trick that comes to mind is putting the file into an AE comp and moving it up or down one line. As long as you render out to the same codec and settings, this should have the effect of swapping the field order.”

  This does work and is a quick and easy way, as long as you interpret the incoming file in AE as progressive, and if you render out progressive again. Otherwise you will lose resolution. But if you do that with progressive settings it will work fine.
• 

  David Issko

  October 9, 2008 at 6:30 am

  Thanks Floh,
  I will try it.
  David
• 

  David Issko

  October 11, 2008 at 6:27 am

  Floh, How were you able to conclude that the field dominance should be off?
  Thanks again
  David
• 

  Floh Peters

  October 11, 2008 at 12:05 pm

  [David Issko] “Floh, How were you able to conclude that the field dominance should be off?
  “

  The trick here is that if you move down an image one line, you actually swap the fields. First field is on line 1,3,5,…, second field is on line 2,4,6,… If you set the incoming image to interlaced footage, AE creates the double amount of full frames, interpolating the missing lines for each field, which is not what you want in this case. You do want the original lines of the whole image to be moved down a line, creating a field swap, without interpolating anything.
• 

  David Issko

  October 11, 2008 at 9:59 pm

  Thanks Floh.

  This job was really getting on my nerves and couldn’t see the big picture. Tight deadline and lots of other work to do. Explanation makes perfect sense.

  By the way, it worked a treat.
  Best wishes
  David

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