A color television broadcasting standard that was first developed in France, SECAM (Séquentiel Couleur à Mémoire) was introduced in the early 1960s and implemented in many countries, including France, the former Soviet Union, and various Eastern bloc countries. It was a unique method of broadcasting color information, transmitting color information sequentially rather than simultaneously, using a memory circuit to store one line of color information, which is then applied to two lines of the image. This method aimed to eliminate certain types of artifacts and provide a more stable and consistent color reproduction than NTSC.
Sequential Color with Memory
SECAM was one of three major analog color television standards, the others being PAL and NTSC. Similar to PAL, a SECAM picture is made up of 625 interlaced lines and displayed at a rate of 25 frames per second (except SECAM-M). However, because of how SECAM processes color information, it is not compatible with the PAL video format standard.
- SECAM video: SECAM video is composite video; the luminance (luma, monochrome image) and chrominance (chroma, colour applied to the monochrome image) are transmitted together as one signal.
Transition to Digital Broadcasting
All the countries using SECAM have either converted to Digital Video Broadcasting (DVB), the new pan-European standard. With the shift towards digital television, the relevance of these analog standards has diminished, as digital broadcasting and high-definition standards have taken precedence. SECAM has been phased out in most areas, with digital systems providing higher quality, more channels, and additional services like electronic program guides and interactive television.
Legacy and Compatibility
Despite these differences, the three systems, NTSC, PAL, and SECAM, were roughly equivalent in picture quality and resolution, with their main differences lying in the method of color transmission and regional electrical standards compatibility. However, the legacy of SECAM remains in certain regions and contexts, such as the resale market for vintage equipment, where SECAM compatibility may still be a selling point for consumers with a need for such technology.