Single-cable analog signal carrying luminance and chrominance together — standard on legacy broadcast gear and CRT monitors. Rarely used in contemporary digital workflows.
Anyone working with archival material or legacy sources will inevitably encounter Composite Video — the analog video signal that compresses luminance, chrominance, and sync pulses all onto a single line. One line, one connector (usually RCA), all image information. This sounds practical but leads to massive quality loss through signal mixing. In the digital workflow of a modern VFX house, you only need this when juggling material from the 80s, 90s, or older broadcast sources.
Practical relevance: If a client hands you VHS archives or old U-matic tapes, you'll have to digitize the composite signal — with all the compromise issues that entails. Chroma bleed occurs with sharp transitions or strong color contrasts: color information bleeds into areas where it doesn't belong. Unlike Component Video (where Y, Pb, Pr travel on separate lines) or even digital standards like SDI or DCI, you immediately lose resolution potential and color accuracy here. When upscaling such materials, you'll later need aggressive denoising and deinterlacing routines to make the signal usable at all.
On set, you practically don't encounter composite video anymore — even consumer cameras have long delivered digitally or at least via HDMI. But in post-production, especially for restoration or archive digitization, it's a necessary evil. You need the right AD converter, a stable source, and above all: realistic expectations about the output quality. Chroma subsampling (4:2:0 or even more aggressive) is already hardwired into the signal generation — you can't get that back later. Those working with such material quickly become friends with color correction and targeted filtering to minimize the typical composite artifacts. It's artisanal, unglamorous, but necessary — especially when it comes to salvaging old productions.