Laserdisc

Lasersisc has been around for a number of years as a home cinema video source. This page explains the format in more detail, and describes the features available of both the software and the Laserdisc players themselves.
LASERDISC

 

 

 
   

LASERDISC

The original home cinema format was intended as an improved video source compared to video cassette. They improve on the video format in terms of sound and picture quality, and also are unlikely to suffer from wear over time. Although Laserdisc has been around for a number of years, it has never really been universally adopted as a home cinema source, mainly due to the cost of the players and the discs themselves, plus the size of the discs were rather large while everything technological was getting smaller and easier to handle. People preferred the existing VHS video format that was readily available, costs less in terms of both players and cassettes, and you could record onto blank discs, something Laserdisc has never been able to do. So the Laserdisc was confined to a niche market of home cinephiles, where it remains today. There are vastly more Laserdiscs available than even the American DVD catalogue, and because of this players have continued to sell. Bargain hunters looking to upgrade from VHS video, or to complement a DVD based home cinema, are having a bit of a good time at the moment as existing software stockists sell-off their UK PAL Laserdiscs at ridiculously low prices (about £5 to £10) to clear the way for increased DVD supplies.

 
   
Laserdiscs are similar to normal CD discs, but are 30 centimetres diameter, the same as a vinyl album. Digital information is encoded onto the disc in the form of pits which are read by a laser pickup as a digital signal. There is no contact between the player and the disc, so the long term quality of the recording will not reduce unless the surface of the disc is physically damaged by scratching. A single side of a Laserdisc can hold up to 60 minutes of picture and sound, making it necessary for most movies to be encoded onto two, three or even four sides (one or two double sided discs).  
   
Soundtracks vary depending on the picture format of the disc. PAL Laserdiscs are usually encoded with a Dolby Surround soundtrack that can be heard as either a stereo signal through a television or external amplifier, or as surround sound through a Dolby Pro-Logic decoder. American NTSC discs can contain these sound formats and can also be encoded with a digital surround format such as Dolby Digital or DTS. The extra information needed for digital surround often means that the stereo soundtrack is left out. PAL Laserdiscs can't be encoded with a digital surround format.  
   

Sound and picture information is encoded onto the Laserdisc in digital form and is converted to an analogue signal by the internal DAC before arriving at the television / amplifier. Picture information is encoded with 400 horizontal lines resolution, not as much as DVD but a big improvement over VHS video. Most Laserdiscs contain a picture with the original widescreen aspect ratio, although some of the older discs, many containing remasters of popular television programmes, are recorded in the 4:3 ratio.

 
   

LASERDISC PLAYERS

Laserdisc was the first dedicated video source for true Home Cinema use. It uses large 12" discs similar in appearance to CD to carry video and audio information. Although Laserdisc was not adopted as much as the creators had hoped, the format still enjoys a fairly successful role as a Home Cinema source. A standard player will also be capable of playing audio CD and Video CD but the sound quality can't compare with that of a dedicated CD player or a DVD player. Laserdisc players come with a wide variety of different options depending on what type of discs you want to play and the type of special features you require.

 


Pioneer CLD-D925 Laserdisc Player

 
 
 

Double Sided Playback

Laserdiscs can hold upto 60 minutes of movie information on a single side, so most movies come on one or even two double sided discs. Players with double sided playback have a laser pickup both above and below the disc so you don't have to turn it over at the end of a side, although nobody has yet invented a player that can change a disc for you!

   
 

PAL / NTSC Playback

PAL standard Laserdiscs are widely available if you know where to look. However, American NTSC discs imported into the UK are also available, with some releases appearing on NTSC before the movie is released in UK cinemas. A dual standard player will play both types of disc but you will need a television that can display an NTSC picture and imported discs are usually more expensive than the PAL release. If you want to watch NTSC discs with a Dolby Digital or DTS soundtrack, NTSC capability is essential.

   
 

Digital Surround Sound

PAL Laserdiscs come with either a stereo or a Dolby Surround soundtrack for playback through a Dolby Pro-Logic decoder. Digital surround such as Dolby Digital and DTS can only be found on NTSC discs. Dolby Digital and DTS soundtracks need a separate digital decoder to process the sound. Make sure that your Laserdisc player can read the sound format you will be using.

   
 

Digital Audio Outputs

Players capable of reading NTSC discs with digital surround soundtracks will have either a coaxial or optical digital output for connecting to a digital surround decoder. Some players have digital outputs for the addition of an external digital to analogue converter (DAC) to improve the sound quality of stereo and Dolby Surround audio signals.

   
 

RF Demodulator

This bit of equipment is required if you want to play NTSC Laserdiscs encoded with Dolby Digital or DTS soundtracks through an amplifier or digital decoder with a digital input. The demodulator changes the sound data on the disc into a data stream that can be used by the digital input and Digital-To-Analogue Convertor (DAC). Some amplifiers have them included, but more likely you will need to buy a separate unit.

   
 

Video Outputs

A Euro A/V SCART socket is usually provided for connection to a television. Some players also have outputs for S-Video and/or composite phono video.

   
 

Phono Audio Outputs

Two phono output sockets are usually provided for connecting the player to an amplifier using a pair of phono leads. If you are connecting to a Dolby Pro-Logic amplifier, the sound information is sent as a two channel stereo signal through phono interconnect cables.