Apple Final Cut Express HD - Manual (Page 766)

766 Part IX Effects
Pixel Aspect Ratios in SD Video Signals Versus Computer Displays
Standard definition (SD) video images use pixels with a non-square (rectangular) aspect
ratio, while computer displays represent images using a grid of pixels with a square
aspect ratio.
SD NTSC pixels are taller than computer pixels and SD PAL pixels are wider than
computer pixels. As a result, a 720 x 480 pixel image looks different (taller) on an NTSC
video monitor than it does on a computer display. 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:
The Viewer and the Canvas let you display non-square pixel video correctly on the
computer’s screen. This option is in the View pop-up menu in both windows.
Note: High definition video uses only square pixels, so it doesn’t show this discrepancy.
720 x 486 Broadcast
(720 x 480 DV)
640 x 480
Looks right
on a video monitor
NTSC square vs. non-square pixels example
Looks wrong
on a computer monitor