Ahh, the technology that, yesterday, we had so much hope for.
Laserdiscs were large metallic discs, much like large CDs, used for playback of video.
Laserdiscs can kind of be considered the precursor to DVDs, with just a few exceptions:
- They were HUGE. 12″ (30cm) in diameter. The same size as a vinyl LP.
- The video was recorded entirely in analogue; audio was sometimes analogue, sometimes digital. DVD’s are all digital.
- Competing formats: Constant Linear Velocity (CLV) and Constant Angular Velocity (CAV)
- CAV discs could only hold around 30 minutes of footage per side.
- CLV discs could hold about 60 minutes per side, but even so you’d have to change sides manually half way through (though some 2 sided players existed). Also, CLV discs generally didn’t support freeze frame!
- No extra features
- Some problems with bleeding frames – if the disc was warped you could often see parts of the next or previous frames (only on CLV discs though)
- Players were quite noisy as it takes a bit of oomph to spin a large metal disc!
- If the motor jammed it could send a flying disc of metal out of the player at a hundred miles per hour. Several decapitations were reported
OK, so I made the last one up 
LaserDiscs, amazingly, were only completely discontinued last year, mainly because they still had quite a following in Japan. They had less of a follow in the US and were virtually unknown in Europe (though I have seen one or two).
LaserDiscs actually held a couple of advantages over VHS cassettes, the competing technology of the time:
- It’s cheaper to stamp discs than to make multi-part cassettes which hold the tape and spoolers
- Picture quality was greater (420 vs 250 horizontal lines) on a LaserDisc than VHS
- LaserDiscs don’t snap in the player, don’t require physical contact with the playing surface which gradually wears it down, and don’t stretch like tapes
Originally marketed as DiscoVision in 1978, the name was changed to LaserDisc in the mid to late 80s. By the time they were discontinued in January 2009 over 360 million units had been produced.
