Apple Motion 4 - Manual (Page 1413)

SD NTSC pixels are narrower than computer pixels and SD PAL pixels are wider than
computer pixels. As a result, a 720 x 486 pixel image looks different on a computer display
than it does on a video monitor. For example, if you capture a clip of video with a globe
in the picture, export a frame, and look at this frame in a graphics application, you’ll see
something like this:
Looks right
on a video monitor
NTSC square vs. nonsquare pixels example
Looks wrong
on a computer monitor
The Canvas let you display nonsquare pixel video correctly on the computer’s screen
using the Correct For Aspect Ratio command in the View pop-up menu above the Canvas.
Note: High definition video uses only square pixels, so it doesn’t show this discrepancy.
Differences in Color Between Computer and Video Graphics
You should also be aware that the range of colors that can be displayed on a broadcast
video monitor is much smaller than that which can be displayed on your computer. For
this reason, colors that appear bright and clean on NTSC or PAL video can seem duller
when viewed on your computer.
If you output graphics images with colors that go outside the “legal” range for video,
they will appear oversaturated, and may “bleed” into other parts of the image. This
distortion can be easily avoided by controlling the palette of colors you use in your
graphics program. As you create the graphics you’ll be outputting to video, resist the
temptation to use the brightest and most saturated shades of color available in your paint
program.
Using Fonts and Creating Line Art for Video
When creating line art or selecting a font to use for a broadcast video image, you should
avoid creating horizontal single-pixel lines, or using fonts that are too thin. Because video
is interlaced, single-pixel lines will flicker as the field in which they appear alternates on
and off. This results in “buzzing” in your graphics, with the buzzing becoming more
pronounced the closer the thin areas in your image are to horizontal.
1413 Appendix B Video and File Formats