One half of a complete picture (or frame ) interval, containing all of the odd or even scanning lines of the picture.

Field Frequency

The rate at which a complete field is scanned, normally 50 times in Australia and 60 times per second in North America.

Field Sequence

A television frame , or picture, comprises two fields. Each successive frame of component 525 and 625 line television repeats a pattern and so can be edited to frame boundaries – like film editing.

Composite video, coded as PAL, NTSC or SECAM, carries colour information on a subcarrier whose cyclic pattern repeats over a longer period – 4 frames in PAL and 2 frames in NTSC or SECAM.