• Canon Cameras

  “blemish” on footage

  Posted by Ruby Gold on April 6, 2005 at 11:50 pm

  I’m looking at interview footage I shot with my GL2 in PPro 1.5. It looks good, but in one scene in one frame a blemish appears that looks sort of like a small circle of “fried pixels.” Viewed close-up it’s an 8 x 8 square of black, white and grey pixels incongruent with the rest of the image. It’s only on one frame.

  Does anyone know what this is–what caused it–and how to avoid it? Thanks-

  Bouncing Account needs new email address replied 21 years, 1 month ago 2 Members · 5 Replies
• 5 Replies

• 

  Bouncing Account needs new email address

  April 7, 2005 at 4:23 am

  It sounds like a “drop-out” and you avoid it by not using video tape.
  Drop-outs are just a fact-of-life with magnetic media.

  Most of them these days are completely masked by error-correction in digital formats, but very occasionally one will be severe enough to show.

  Just be happy you’re not shooing on analog BetaCam.
• 

  Bouncing Account needs new email address

  April 7, 2005 at 4:26 am

  BTW, you can “fix” this in editing by covering the “blemish” area with a matching section of the previous frame (or next frame) that is “clean”.
• 

  Ruby Gold

  April 7, 2005 at 4:45 pm

  Thanks for the response–your fix was just what I had in mind–I just didn’t understand why it was on there in the first place–hadn’t experienced it in other shoots.

  Also, no dropouts “registered” when I was capturing in PPro 1.5–is that a different kind of dropout? And, there’s absolutely no way to avoid them, eh?
• 

  Ruby Gold

  April 7, 2005 at 4:50 pm

  Thanks for the response–your fix was just what I had in mind–I just didn’t understand why it was on there in the first place–hadn’t experienced it in other shoots–and if there was some thing I could do to avoid them.

  Also, no dropouts “registered” when I was capturing in PPro 1.5–is that a different kind of dropout? Lastly, what did you mean when you said that most of them are “completely masked by error-correction in digital formats?” And, there’s absolutely no way to avoid them, eh? Damn…

  thanks again-
• 

  Bouncing Account needs new email address

  April 7, 2005 at 9:34 pm

  [Ruby Gold] “what did you mean when you said that most of them are “completely masked by error-correction in digital formats?””

  It means there are AWAYS drop-outs over the course of virtually any tape.
  In analog systems, the “mask” is usually very visible, in digital formats the error-correction completely covers maybe 99.5% or more, so they go unnoticed.

  As to the software “registering” a drop-out:
  At the digital import level, unless the TimeCode stops or the entire image is lost to a head-clog or severe tape problem (i.e. a crease) the computer doesn’t even “know” there IS a drop-out.
  Only to your EYE might there appear to be something amiss in the video.

  And, trust me, if its just a frame or two with a “blemish”, do the “dance of JOY”!

  We who have come from analog BetaCam (and earlier) know what simple tape drop-outs can truly “do” to a video image.

  Again, without actually SEEING your “blemished” tape image, I am only speculating about it being a drop-out… but it sure sounds like that’s what it is.

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