Doom9's Forum - View Single Post - NEW PROJECT: Star Wars Trilogy The Definitive Collection Laserdisc To DVD Project

Kedirekin · 3rd January 2002, 05:31

I think the brochures must be *very* dumbed down. Remember that a laserdisc is two sided. The laser doesn't shine 'through' the disc, and if it did, it'd pick up two 'pictures'.

I'm virtually certain that a laserdisc basically contains the original broadcast FM modulation encoded as pits of varying length on the disc (as hinted at in the 'producing a laserdisc' article - too bad there isn't a 'how playback works' article). The vertical ramp signal might be removed on the disc and added back by the player, but the concept of directly recording the modulation of the FM signal is the same, and much more in keeping with the capabilites of 70's technology. The laser pickup just has to be a very fast intensity sensor.

3rd January 2002, 05:31	#14 \| Link
Kedirekin Registered User Join Date: Oct 2001 Location: Minnesota Posts: 1,110	I think the brochures must be very dumbed down. Remember that a laserdisc is two sided. The laser doesn't shine 'through' the disc, and if it did, it'd pick up two 'pictures'. I'm virtually certain that a laserdisc basically contains the original broadcast FM modulation encoded as pits of varying length on the disc (as hinted at in the 'producing a laserdisc' article - too bad there isn't a 'how playback works' article). The vertical ramp signal might be removed on the disc and added back by the player, but the concept of directly recording the modulation of the FM signal is the same, and much more in keeping with the capabilites of 70's technology. The laser pickup just has to be a very fast intensity sensor.