Chapter 1: What is a Laserdisc?



 
 
"Laserdisc is not dead. It has only retired."
 

We are living in the age of DVD. The high-resolution optical video disc has finally hit the mainstream. Millions of units have been sold, mass public awareness is on the rise, and someday it may even achieve the long-awaited replacement of low-quality VHS as the default home video standard in American households. Assuming, of course, that it isn't made obsolete in the meantime by the next big fad.

DVD has brought many new consumers to the home theater hobby who were previously unaware that an alternative to low-resolution videotape existed. The temptation is to hail DVD as the greatest invention since color television. Unfortunately, that is quite unfair. In fact home theater consumers have had access to high quality video disc technology for almost two decades. Why is it that no one else adopted this format? Frankly, until recently no one else cared.

The Features

A laserdisc is a 12-inch platter capable of 425 lines of NTSC resolution. In comparison, VHS barely manages 250. Laserdisc is a dramatic improvement over videotape, yet somehow it never caught on beyond a small niche of consumers. This can be attributed to a few factors: the large size of the discs, the side breaks, the lack of marketing, and the overwhelming apathy of the TV-watching public. Most prohibitive was the price. At its height, a typical movie-only disc would cost approximately $35, with some of the deluxe box sets reaching upwards of $125.

To justify this price, laserdisc manufacturers pioneered (no pun intended) many of the features that DVD consumers can now take for granted: digital audio (along with Dolby Digital and DTS), THX mastering, secondary audio channels, commentary by the filmmakers, and supplemental material about the movie in question. The best box sets were archives of information detailing every aspect of the film's production. Some could take days to peruse.

Laserdiscs come in two prominent flavors: A CLV-format disc can contain up to one hour of material per side, and a CAV-format disc will hold up to 30 minutes per side. The advantage to CAV is that it will have a slightly sharper picture, will have slightly more stable colors, and allows access to freeze-frame and slow-motion functions. For the most part, visible difference between the two is slight and a mid-level laserdisc player with digital field memory can simulate the freeze-frame and slow-motion functions on CLV, but with reduced resolution in these modes.

Any laserdisc player will be compatible with both CLV and CAV, and many disc titles contain a mixture of both formats, sometimes CLV on one side of a platter and CAV on the other. In addition, many players have auto-turn mechanisms built in to make side changes less obtrusive. The typical auto-flip side change lasts about 7 seconds. Depending on the player, the screen may appear entirely black or may freeze on a still from the movie during the pause. Any movie with a running time over 2 hours will require a second platter, and this means getting up to change the disc.

When DVD hit the market in the late 1990's, it was given a huge marketing push that has been very successful in educating consumers on the benefits of high-resolution video. DVD is essentially a refinement of laserdisc technology. The disc size is smaller, resolution is modestly increased about 15%, side breaks are for the most part eliminated, and most importantly the price is lower. At this point, most DVDs cost approximately $19.99 - $24.99. It has been very popular as a result.

The Video

Even though a laserdisc may look like an oversized CD (or DVD), the picture signal it carries is actually analog in format. Only the PCM audio tracks are digital.

In direct comparison on a typical television monitor, the difference in picture quality between laserdisc and DVD is noticeable but slight. DVD is a little sharper and can achieve deeper colors without introducing signal noise as some poorly-mastered laserdiscs will. A well-mastered laserdisc, however, will hold up very well and, depending on the respective mastering quality, may even look better than a comparable DVD edition of the same film.  For those with more expensive video display equipment, both formats allow S-Video connection for better color clarity. DVD goes a couple of steps further by also offering the advanced component-video connection as well as 16:9 anamorphic enhancement for increased resolution on widescreen monitors, which are advantages in its favor.

The Sound

The audio is a different story. Listening in 2-channel stereo, laserdisc audio almost always sounds richer and fuller than its compressed DVD counterpart. DVD sound quality is generally acceptable, but barring substantial mastering differences the 2-channel downmix sounds thinner and less vibrant than the uncompressed PCM audio on a laserdisc. Both formats offer Dolby Digital and DTS 5.1 channel surround sound for those with high end audio equipment, and these soundtracks tend to be closer in quality (with the edge still usually going to laserdisc).

As for the reasons why this happens, there are several factors at work:

Laserdiscs have four separate and distinct audio channels. Two carry the PCM digital stereo signal and two carry the analog stereo. If a laserdisc includes a Dolby Digital 5.1 track, that signal is distributed in RF-modulated form through one of the analog channels. The other analog channel usually has either a mono sound mix or an audio commentary. This leaves both digital stereo tracks free.

The advantage to this method is that the 5.1 mix and the stereo or Dolby Surround mix are kept forever separate.

DVD has the potential for even more audio tracks, but the disc producers almost never use them for this purpose. They usually fill them with extra commentaries or foreign-language soundtracks, if anything. DVD also has one feature that sounds in theory like a great innovation but winds up being its greatest curse. All of the audio on a DVD is Dolby Digital-encoded. The player then is capable of taking the 5.1 mix and (within the player itself) down-converting this into a regular 2-channel stereo or surround mix for those people who don't have 5.1 surround sound.

Why this is such a problem? In preparing the audio for this down-conversion process, many compromises have to be made. One of two things usually happens:

1) The disc producers will favor the 5.1 track at the expense of the stereo downmix. One common mistake is to direct all of the bass in a soundtrack towards the LFE channel, leaving none whatsoever for the stereo mix. If you listen to it in stereo or Pro-Logic, therefore, important parts of the sound design may be practically silent. Or,

2) The disc producers will compromise the 5.1 track in order to accomodate more favorable down-conversion. If listening in Dolby Digital the bass is not going to be as deep as it should be, and the discrete sound effects will be limited.

This second process is the more common and leaves both soundtracks at a disadvantage. So you see, it's really the worst of both worlds. A simple fix to this would be if all disc producers would simply include separately both a 5.1 mix and a 2.0 mix on the same disc. A few do this, but very few and it is becoming rarer all the time. Even when they do, the 2.0 mix is not going to sound as good as the uncompressed PCM digital on laserdisc, but it will at least be closer and the 5.1 should be the same on both.

Given this, one might think that DTS audio, which remains separated from the PCM or Dolby Digital mix on a disc, would remain uncompromised. Sadly, this is not the case. DTS requires significantly more disc storage memory than Dolby Digital. In order to keep everything on a 5" platter, this means that either the bitrate allotted to the picture quality must be reduced to make room, or the DTS signal must be processed at a lower bitrate. Again, these compromises are not necessary on the laserdisc format.

The Legacy

I cannot deny that the introduction of DVD has effectively destroyed the market for laserdiscs in the United States. This is a bittersweet end to the format, having never achieved the mass-market respect that it deserved. It had a hell of a run, though. In the years before DVD, laserdisc was the definitive collector's medium for high resolution video, producing a tremendous volume of output (estimates say approximately 15,000 titles) and some of the finest archive editions of classic movies, many of which may never be reproduced on DVD due to rights issues.

During its prime, there was something very special about being a laserdisc collector. It was like belonging to an elite club of enthusiasts, each of which feeling that they were among the very few who actually cared about the presentation of movies on video. In my own town of Boston, there was once a store called LaserCraze which issued all of its purchases and rentals in plastic shopping bags with a distinctive orange spiral logo. If you walked down the streets and saw one of those bags you would know that someone else out there shared your feelings, even if you knew nothing else about that person. Now that DVD has gone mainstream, it has brought a great deal of respectability to the hobby but has also made the bandwagon a little too big to retain that sense of community.

Let's not forget that just because new titles aren't being produced does not mean that existing titles will cease to play. In fact, barring laser-rot (an unfortunate manufacturing defect which causes a very small percentage of laserdiscs to develop video interference) they'll last a whole lot longer than those damn videotapes which degrade with each play. In addition, unlike the region-blocked DVD players, any laserdisc player purchased in the United States will be compatible with NTSC discs imported from Japan or Hong Kong, both of which also had active laserdisc markets.

It is for these reasons that I suggest we cherish our laserdisc collections rather than discarding them. This web site has been designed with that purpose in mind. Though only a few articles are available so far, I hope eventually to have reviews ready for each of the laserdisc titles in my collection. To begin, I have a heavy emphasis on Japanese laserdisc releases because they are less commonly reviewed in other sources. I will soon be expanding to domestic titles, both common and obscure, in the near future. I hope you find the site both informative and enjoyable.


 
Chapter 1Chapter 2Chapter 3
Chapter 4Chapter 5Chapter 6
Chapter 7Chapter 8Chapter 9
Jump 10 Chapters
Previous ChapterNext ArticleNext Chapter
Previous PageNext Page

STEP FORWARD TO CONTINUE
OR SKIP TO NEXT CHAPTER


Return to Chapter Listing

 
 

All material on the Laserdisc Forever web site or its corresponding pages is ©2005 by Joshua Zyber. Any unauthorized use is prohibited.