ABSTRACT
Much video employed a trick in which each frame of the image contains visual information from two different points in time. There are a number of nonintuitive technical issues – including interlaced fields, frame rates, frame sizes, pixel aspect ratios, safe image areas, and color spaces – that differentiate video and that must be handled properly to ensure final work appears on television as intended. Mismatches in frame rates between 30 and 29.97 can cause audio/video synchronization errors, as well as skipped or repeated images. Along with the oddball frame rate of 29.97 comes two different ways to number the frames: drop-frame timecode and non-drop timecode. Some video cameras also shoot at this rate and add pulldown to simulate film-like motion. An important video issue is the luminance range of source footage. The cure for interlace-based field flicker is to soften the transition from horizontal lines to their adjacent pixels.
