Understanding the PAL Video Format
Jaime Estrada-Torres, London Film School
The Phase Alternate Line (PAL) color encoding system scans images into 625 horizontal lines to form a video frame every 1/25 of a second. There are 2 fields per each video frame, which results in 50 fields for every 25 frames in each second. It is also possible to telecine with 2-2-2-2-2-2-2-2-2-2-2-3 cadence to produce video that plays without speed change, but at the cost of the one-to-one relationship between timecode and key code, as seen in Figure A2.1. This would, therefore, be inappropriate for a film edit, but may be used for video finish projects. The PAL system allows for a more defined color rendition than that of an NTSC image.