Q: What is NTSC, ATSC, PAL, and SECAM that I see related to television and DVDs?

A: The short answer is - they're types of broadcast signals, and different regions of the world use different types. The letters stand for:

• National Television System Committee
• Advanced Television Systems Committee
• Phase Alternating Line
• Sequential Color With Memory (In French, Séquentiel Couleur à Mémoire)

Q: What signal is used in what region?

A: Have a look:

NTSC is the video system or standard used in North America and most of South America. In NTSC, 30 frames are transmitted each second. Each frame is made up of 525 individual scan lines.

ATSC is the new and improved NTSC signal, made for digital/HD broadcasts.

PAL is the predominant video standard used mostly overseas. In PAL, 25 frames are transmitted each second. Each frame is made up of 625 individual scan lines.

SECAM is used primarily in Eastern Bloc countries, as it was initially adopted to prevent reception of Western broadcast signals. Most SECAM-capable devices now include a dual standard PAL/SECAM decoder.

Q: Can these signals be converted?

A: Yes, there are converters for most broadcast signals. For instance, you could attach a PAL DVD player to an NTSC television with a converter.

However, DVDs encoded in one format will not play correctly on a device of another format. (i.e. - a PAL DVD will not play in an NTSC device.) The DVD will need to be copied to a computer and then re-burned to a disk, being converted in the process. This process is generally tedious and there will be a loss of video quality in the conversion, so it's really not worth the effort if the DVD is already available in the desired format. (Meaning - it would be easier to just buy the DVD in the right format rather than convert it over.)