• Adobe After Effects

  4:3 Center Cut Guides are Wrong

  Posted by Ryan Sears on March 5, 2009 at 8:45 pm

  The 4:3 center cut guides in CS4 are wrong by default.

  The Center Cut Action-Safe should be 32%
  The Center Cut Title-Safe should be 40%

  This is if you are working in HD 1920 x 1080 and need guides for 4:3 center cut.

  I am still trying to figure out why these were wrong to begin with. maybe they are right for a different format but they are definitely wrong for 1080HD.

  Paul Conigliaro replied 17 years, 2 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Paul Conigliaro

  March 5, 2009 at 9:22 pm

  This really doesn’t surprise me. That along with Adobe suddenly deciding that D1 16:9 square pixel is 872×486 make me doubt a lot of the default measurements.

  CS3, FCS2
  [Note: Using Particular, 3-D Stroke, and now Form do not instantly make your designs “teh awesome.”]
• 

  Paul Conigliaro

  March 6, 2009 at 5:52 pm

  Previously (CS3 and below) it was 864. Now it’s 872.

  Adobe says the change is because of a discrepancy between “production aperture” and “clean aperture.”

  The problem comes in when you leave the Adobe universe. As far as I know (at least in Avid and FCP) the renders come in slightly letterboxed. However, this only affects SD square pixel comps.
• 

  Paul Conigliaro

  March 7, 2009 at 5:30 pm

  After talking to a few video engineer-types, it turns out that the conventional wisdom for the square pixel sizes in graphics for NTSC & PAL are wrong. The clean aperture is 4:3, but the production aperture is slightly wider. The square pixel sizes were incorrectly calculated from assuming the production aperture is 4:3.

  I guess if we were to exactly measure, say, a circle which was created in a sq. pixel comp in the traditional settings (720×540 or 864×486), it would be every so slightly stretched. So, in order to completely fill the production aperture and maintain proper aspect, the new values were calculated.

  It took a while before I could wrap my head around that, but that is why CS4 now uses, for example, .91 (10/11) for the PAR in NTSC.

  (Between that, looking at this article on time, and talking to a friend about Schrödinger’s Cat/Quantum Suicide, my mind was pretty messed up yesterday.)

  CS3, FCS2
  [Note: Using Particular, 3-D Stroke, and now Form do not instantly make your designs “teh awesome.”]

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