Tuesday, July 20, 2010

Laserdisc Players and Laserdiscs - Formats and Features

Laserdisc and Laserdisc Player Formats and Features

There's a lot of confusion about laserdisc players and the formats that they will or won't accept. This is a brief guide to the formats and what to look for in a player.


What is a laserdisc?


It's a large (12 inch) optical disk that looks like a giant CD but is the sames size as an old vinyl LP. An 8 inch format also existed but is very rare, and there have even been a few CD-sized releases, mostly in the CD-Video format (see below). Thelargerdisks should normally be supplied in a cardboard sleeve (like an LP sleeve), with a plastic or plastic-lined inner sleeve. They hold video in an uncompressed analog format, which means that there's a maximum of about 45 minutes of video and sound on a side in the highest quality format, CAV, up to an hour in the alternative CLV format (see notes below). You have to turn them over to view both sides. Some players will do this for you (or rather, they'll move the playing head from one side of the disk to the other), usually they're the more expensive models. Many enthusiasts believe that a good laserdisc gives a higher quality picturethan DVD, since the picture lacks jagged lines and other artifacts caused by digital compression.


Laserdiscs were manufactured for older TV formats, not modern widescreen sets; if a laserdisc is marked as widescreen that almost alwaysmeans that the picture is letterboxed. There were a very few special 'squeezed' disks made with a genuine 6:9 picture on them, but they were given away with widescreen TVs, never sold commercially, and are extremely rare.


Surprisingly, laserdisc players stayed in production until January 2009, when Pioneer ceased to manufacture the last models, the DVL-919, DVK-900 and DVL-K88. All of these were NTSC-only models aimed at the Japanese market; European versions were also made, but ceased production much earlier.


Why is there confusion about formats?


Several reasons:



There were separate PAL and NTSC formats, and most players designed for the US market can only handle NTSC. European players can often handle both, especially later models, but this isn't always true. Some will only play PAL. Changing this requires extensive modification of the player electronics, and components and circuit boards that are probably no longer available. You're better off buying the right player to begin with.
The earliest laserdiscs only had an analog sound track; later the specification added digital sound tracks. Laserdisc players that can play digital sound laserdiscs should also be able to play CDs and the CD-Video format, basically anordinary-sizedor8-inch CD with an analogue video track - sometimes full-sized laserdiscs are also made in the CD-Video format.
A few of the really late models can also play DVDs, but performance isn't likely to be anywhere near as good as a modern DVD player.
Some low-end late-model laserdisc players dropped the ability to play the old analog sound tracks, and if you have old disks you may want to avoid them.
Some NTSC disks have Dolby AC-3 surround sound tracks. To get the benefit you need a laserdisc player that can decode the sound, and a home cinema amp that has the special signal input needed for this format, or a decoder box that sits between the player and the amp. European users should think VERY carefully before going the AC-3 route, because it's expensive and will only work with American disks! Just to add to the confusion, there are also some disks with DTS sound, but VERY few players that can play it. AC-3 disks lose one of the analogue sound tracks, DTS disks lose both.
Laserdisc players will not play CD-ROMs or CD-i disks. A few will play Video-CD (a digital video format which is different from CD-Video) but this is comparatively rare; since most computers can play Video-CD this was never a priority for laserdisc player manufacturers, and most lack this capability.

You may also occasionally see references to 'videodiscs','CEDlaserdisks', 'selectavision disks' or 'laserdiscs in hard plastic cases'. These are usually a completely different type of disk, resembling a giant floppy disk, which will only play in a Selectavision / CED player. You really don't want to go there unless you're a collector of obscure electronic equipment; a tiny number of films were released in this format, and all of them are available on laserdisc and DVD at much higher quality.


There was a recordable laserdisc format, but the recorders are often larger than a standard Hi-Fi rack can hold, and when last available the disks cost in excess of $1000 EACH. However, they tend to be very good players, and can often be used as video mixers with an external recorder.


What should you look for in a player?


Check the specification - make sure it does everything the seller says it does. You can find specifications for many playerssoldintheUKandEurope at the LaserDisc UK Web Site - laserdiscarchive.co.uk . Be wary if everything you see in a lot description, including the pictures, comes from this site! You want to see what the player you're buying looks like, not the showroom photos that accompany most of the entries on this site. That said, the main things to look for are as follows:



First and foremost, you need digital and analogue sound. There are enough old disks around that you will probably want analogue sound, while some later disks (and all CD-Video disks) are useless without digital sound.
If you're in Europe you want PAL video and (if your TV can handle it) the ability to play NTSC disks in 'PAL 60' or 'Pseudopal' format. There are a lot more NTSC titles than PAL.
If you're in the USA you probably only need NTSC - few American TVs can handle PAL, and there are very few PAL titles that aren't also available on NTSC disks. If you do need PAL for some reason, you'll probably also need an external PAL to NTSC video converter.
If you've got an AC-3 decoder and amp you will want a player that has AC-3 sound. DTS is also useful, but not common enough to be worth worrying about. Players that can handle DTS will usually have a digital output compatible with most modern amps.
Dual sided play is well worth having, if only to avoid getting out of the chair half way through. Unfortunately many films run to three sides, so you'll still have to move eventually. It's probably good for your legs... More seriously, the changeover time is obviously important, usually it's about ten seconds but some players can do it in less by buffering the signal. Side change is mechanically complex and players that have ittendtobethebettermodels,but may be more prone to obscure problems.
You probably need a remote, and very few 'universal' remotes know about laserdisc players, which can have four different fast forward modes. Think carefully before buying a player that doesn't have one.
European players will usually have SCART, composite video, and phono sound sockets. Some will also have S-Video and/or an AC-3 output. American players won't have SCART. Really high-end players should also have a Toslink optical output for DTS sound, and possibly a digital coax cable (not the same as AC-3).
Some industrial laserdisc players (most notably Pioneer) have a serial socket for computer control. This is unlikely to be useful unless you have a specific need for it. There's little or no software around for controlling them, except for specialist programs embedded in (for example) arcade games and information terminals, but the information needed to program them can be found on line at various sites.
Industrial players may also have an input socket for a barcode reader - it was only ever used on educational disks and is unlikely to be useful for anything else.
Finally, don't forget to check that the player is built to run on the voltage you use!

Why Are So Many Players Sold 'Collection Only'?


Laserdisc players are big, VERY heavy, and easily damaged. I've had two destroyed in transit. Once they're damaged they're very hard to fix; the mechanism has a LOT of high-precision moving components, and has to spin a big heavy disk at high speed. If anything goes badly out of alignment you're in trouble. Collect if you can, or use an insured courier, and make sure that the seller knows that they're easily damaged. They should ideally be transported in the original packaging, if that's not available the minimum is a thick cushioning layer around the player, such as several thicknesses of bubblewrap, with something to absorb impact around that (such as packing pellets) with a strong outer box. I learned this the hard way - so, hopefully, did the sellers who had to give me refunds!


How Should Laserdiscs Be Packed?


Laserdiscs are reasonably strong but vulnerable to cracking and chipping, especially at the edges. They should always be supplied in their sleeves, with an inner liner bag. That should always be protected by a strong mailer or similar - ideally they should be wrapped in bubblewrap and sandwiched between sheets of card, or appropriately sized "pizza boxes". Vendors can often find suitably sized boxes at independent record shops, which still often sell old-style LPs. Be nice to the person behind the counter, and they may be willing to give you all the packing material you could possibly want. Alternatively, several companies sell LP mailers, but you may want to reinforce them.Since this was originally posted someone has suggested that for really rare laserdiscs, where the condition of the sleeve is as important as the disk itself, it might be better to pack the disk in a separate expendable sleeve or bag - but please only do this if you are sure that the replacement sleeve is tough enough to protect the disk, and that the original sleeve is well protected too!


A Note on CAV and CLV disks


CAV (constant angular velocity) disks rotate at constant speed. CLV (Constant Linear Velocity) disks rotate slowly when the head is near the rim, fast when it's near the hub, so that the speed at which the head moves over the video track is always the same. Video quality is roughly the same, although CAV was generally preferred for Special Edition and other high-end releases. The advantages of CAV include freeze frame, variable slow motion and reverse; there's also less chance of sound interference between adjacent tracks. CLV disks can't handle the special play modes, unless the player has a digital frame store, but have more capacity, up to an hour per side. In the early days most laserdiscs sold were CLV, but many of the laserdiscs sold in their last years of manufacture were CAV double disk sets with extra features.

Specialised Laserdisc Players

While most of this guide relates to domestic laserdisc players, the sort of thing that might be part of a home cinema setup, they have a long history in specialised applications such as video arcade games (e.g. the original Dragon's Lair arcade machine), karaoke machines, and a few IT applications, most notably theDomesday Project which used laserdisc players and BBC micros for an interactive encyclopedia of Britain.

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