Apple Final Cut Pro 5 - Manual (Page 1710)

Appendix A Video Formats 359
V
Because the fields are changing at twice the frame rate, there is less perceived flicker
than if each frame was scanned progressively. For example, with NTSC, a field of odd
lines is scanned in 1/60th of a second and a field of even lines follows in the next
1/60th of a second, resulting in a complete frame every 1/30th of a second.
About Progressive Scanning
Progressive scanning is much simpler than interlaced scanning: each line is scanned
consecutively until a complete frame is drawn. Computer monitors and many recent
high definition televisions use progressive scanning.
Here are some significant facts about interlaced and progressive scanning methods:
 Interlacing provides twice the perceived frame rate with only half the recording or
transmission requirements.
 Progressive scanning is preferred when interlacing artifacts (such as thin flickering
horizontal lines) would be unacceptable. Progressive images are often considered
more film-like because there are no flickering interlacing artifacts.
 Computer displays are almost always scanned progressively.
 NTSC and PAL televisions always use interlaced scanning.
 Many high definition video cameras can record progressive frames.
 Video destined for computer-only use, such as web video, should always be
made progressive.
Field 1 Field 2
Frame