LD#04: Laser Disc media quality (historical) Summary revised: 30 Mar 91 Analysis revised: 09 Jan 89 2002-07-14 Note: This article may provide some insight into part of why LD struggled to gain marketshare for 20 years, and then saw DVD blow right past it. Also, this is a cautionary tale for those seeking used LDs. You do need to be careful about quality. Summary Remarks: A reader writes... > For some time I have been considering getting a Laser Disk Player ... > ...However, the apparent problems in quality control among even the best > disk producers is REPEATEDLY reported on this bulletin board....Am I > getting into a technology where I will be returning every other disk for > defects?....It sure sounds like it...Are things improving?...The reported > problem rate seems to far exceed anything I have heard/seen for CDs, LPs, > and audio tapes. Before giving a direct answer, let me ask you to keep two things in mind: 1. Tapes WILL degrade with time. They are an ephemeral medium. (prior to DVD) LD was the only consumer video medium that has a chance at archival life. Although I'd only been in the market for three years when I last revised this article, I had one 1978-vintage LD that plays as well now (in 1991) as it did when it was made. 2. LD consumers are picky. We bought into the technology to get higher quality, so we are by definition more sensitive to defects, even minor ones that go unnoticed on tape. Also, the nature of the disc encoding format results in defects appearing as visual artifacts that are uncommon on tape and broadcast, and therefore more noticeable. The answer(s): A. If you purchase ONLY new releases, you can expect a first-play defect rate of about 2%, and a long-term defect rate of another 2% (for a total of 4%). The 2% is an estimate, because the prognosis for disc longevity is constantly changing as the pressing plants tweak their processes. By comparison, CDs have an initial-defect rate of about 1% and a long term defect rate too low to measure. B. If you buy 1987 or newer back-catalog or used titles, you can expect defect rates of about 4%. C. If you buy pre-1987 back-catalog or used discs, the defect rate can reach as high as 30% (unless the disc was manufactured by 3M, for which the rate is 0% during 1983-1987). There is some really old material still out there. In 1990, I bought a factory-sealed 1981 title pressed by the long-defunct DiscoVision, and a used DiscoVision pressing from 1978. According to a regional dealer (who had been in the video disc business from the beginning), LDs have a higher defect rate than CDs, but a lower rate than tapes and LPs. LP and tape media wear and deteriorate a little with each playing. CDs do not, and seem to be exceptionally stable. The thing that sets LD apart from other consumer media is that some individual discs may degrade with time, whether they are played or not. This is a phenomenon unfamiliar to consumers, and is disconcerting to those expecting LDs to behave like LPs or "12 inch CDs". The phenomenon is known colloquially as "laser rot". It is evidently a deterioration of the data layer due to any of the following: * mechanical shear stress due to bending, warping or thermal cycles. * chemical attack on the data layer from contaminants in the glue. * oxidation of the data layer from gasses contained in voids in the glue, that penetrate the "protective layer" between the glue and data. * chemical attack or oxidation of the data layer from contaminants dissolved in water that migrates thru the glue or exterior acrylic layers (acrylic is slightly hygroscopic). * chemical or oxidation attack through the disc edges (the data layer extends to the inner and outer edges). * relaxation deformation of the data layer due to improper pressing of the acrylic substrate. Laser rot can happen on the dealer's shelf or in your home, and takes anywhere from 2 months to 5 years to become evident. You can minimize your risk by following the tips in my "care & repair" article (LD#13), available separately on request. If you do business only with LD dealers who offer unlimited warranties, you will probably not get burned. I returned for exchange or credit some 20 LD titles in a three year period (of over 250 purchased). 6 were new pressings, 8 were back-catalog and 6 were used.. There are other defects which occur on LDs. I have another article (LD#17) summarizing these (as well as non-defects that people complain about). _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ re: Laser Disc time capsule 09 Jan 89 Note: ^^^^^^^^^ Note, as of 02 Dec 91: I have examined several hundred additional LDs since I wrote this report. Domestic Sony (DADC), Kuraray (Japan), Mitsubishi (Japan) and substantially more Technnidisc production is now reaching the market as well. Until I revise this report (not before 1992), the balance of it is useful only if you buy used discs and/or back-catalog titles. This article reports on the results of a casual investigation into the quality of laser discs (LDs) pressed by four major media manufacturers. It covers 210 disc titles representing production from 1980 to the present. The actual platter count is probably about 250. {Some comments were added on 10 Jun 89, preparing to mail this in response to a request. The new comments are delimited with braces, as is this comment.} A co-worker obtained the idle inventory of a defunct LD dealer in Florida. The discs involved had apparently been in storage for several years. In an unrelated activity, a local (Colorado) LD dealer routinely sells used and "cutout" discs. Most of these discs are obtained from failing dealerships or liquidated personal collections. I have bought more than a few of the local used discs, and they were the primary motivation for taking advantage of the "Florida opportunity". Although I have been buying LDs for less than a year, I have already encountered a significant number of defective LDs. Fortunately, I have been able to get replacements from my primary local dealer. Nonetheless, I am concerned about the long term prospects for my collection and I was interested in taking a peek at the past. Both LD sources (Florida and my own collection) represent a nearly random sample of product from: * MCA DiscoVision Associates (USA, "DVA", aka MCA VideoDisc, Inc.) * Pioneer Video, Inc. (USA, aka Pioneer Video Manufacturing) * Pioneer Video Corporation (Japan, aka Universal Pioneer) * Minnesota Mining & Manufacturing (3M, St. Paul, Minn.) (Note that the distinction is by pressing plant, not by studio, label or distributor.) I say "nearly random" because many of these discs were pre-owned, and presumably DOA discs have already been culled out, as well as some which suffered fast deterioration ("infant mortality"). However, there is a small amount of DOA data present, as I have included all the new discs I have bought in the last year. Table: left number = quantity sampled right number= percent defective +=======+===========+============+============+===========+ | Year |DiscoVision| Pioneer | Pioneer | | | Made | (DVA) | USA | Japan | 3M | +=======+===========+============+============+===========+ | 1980 | 2 50% | - - | - - | - - | +-------+-----------+------------+------------+-----------+ | 1981 | 4 100% | 1 0% | 16 38% | - - | +-------+-----------+------------+------------+-----------+ | 1982 | - - | 5 40% | 19 26% | - - | +-------+-----------+------------+------------+-----------+ | 1983 | 3 67% | 17 20% | 10 30% | 4 0% | +-------+-----------+------------+------------+-----------+ | 1984 | - - | 25 32% | 2 0% | 2 0% | +-------+-----------+------------+------------+-----------+ | 1985 | - - | 20 15% | 2 0% | 3 0% | +-------+-----------+------------+------------+-----------+ | 1986 | - - | 21 10% | 2 0% | 3 0% | +-------+-----------+------------+------------+-----------+ | 1987 | - - | 17 6% | 1 0% | 3 0% | +-------+-----------+------------+------------+-----------+ | 1988 | - - | 9 0% | 1 0% | 13 0% | +=======+===========+============+============+===========+ | Total | 9 78% | 115 18% | 53 26% | 28 0% | +=======+===========+============+============+===========+ Notes: "Defect" = A visible or audible abberation that is unlikely to be in the source material or video master. Defects include: color snow, video "static", noise bars, streaks, speckles, loss of tracking, audio hiss, pops and cyclical ("helicopter") noise. Defects judged to be the likely result of handling damage were not counted (and many of the Florida discs were in rough shape). I counted only defects severe enough that I would endeavor to replace the title, if it were mine. Also, only defective TITLES were counted, not merely defective platters or sides. It only takes one spot on one side of a multi-disc set to ruin the whole title. Defects were located by sampling the beginning and end of each side, plus at play-time intervals of approximately 10 minutes. I did not watch all 210 titles all the way through, so there may be additional undiscovered defects. Year Made= Date of manufacture is somewhat indeterminate. Only Voyager (Criterion Collection) routinely documents "nth Printing, 19xx". Technidisc puts a visible mastering date in the data layer. Everyone else keeps mum. Disney doesn't even copyright the artwork on the package. So, I used the latest date shown on the disc, label or packaging, i.e. the year of earliest possible manufacture. In some cases, e.g. Pioneer Artists, the catalog number is a clue. In the absence of the above, I interpolated the Pioneer batch number stamped or inscribed on the data layers. In any case, most of the discs could easily have been made in a year LATER than the one listed. They could not have been made earlier unless the label post-dated the copyright, which is probably illegal. In particular, since the DVA manufacturing facility was taken over by US Pioneer, the 1981 and '82 US Pioneer production may have taken place in 1983. OTHER LABELS: The sample size was too small to include the following in the above table: Technidisc: USA. I have examined only 3 discs made by this firm. Two were 1988 production and have no apparent defects. The third was mastered on 02/05/85 and had the most severe "laser rot" I have ever seen, with high levels of video and audio noise. A grid-like pattern is visible in the aluminum data layer. It appears to be either the glue or oxidation of the Al resulting from voids in the glue. {I have now seen six Technidiscs from "The Prisoner" series. At least two have unstable chapter numbers and timecodes. I have confirmed that this is a disc problem.} PDO: Philips-Dupont Optical, U.K. I have seen only one disc, new production, with no apparent defects. PDO is the major maker of CDVs and has long experience in CDs. Criterion is now using PDO for non-DigitalSOUND LDs. {I have seen several more PDO discs now, and one disc was mis-assembled. Both sides contained side 1 program material. If this is the only kind of error that PDO can make, I won't worry about them.} Other Japan:I have seen only one, a CBS/Sony, also new production. {Much more Japanese production has since turned up.} Disctronics:(aka LaserVideo and now "Disc Manufacturing, Inc.") I have only seen CDVs from this firm and have no other data. {The initial batch of Reference Recordings LD-101 test discs was made by Disctronics. So far, so good.} CONCLUSIONS: Please draw your own conclusions. For myself, this data confirmed my impressions about the major disc makers. My personal purchase guidelines remain: * I buy 3M product, any vintage, without hesitation. I have encountered defects since writing this report, but I fully expect that once fixed, they stay fixed. * I buy Pioneer/Japan 1987 or later production without hesitation. * I buy any other production only where long-term exchange or replacement recourse is established. Several mail-order dealers offer unlimited dealer warranty. * I buy used/cutout discs only where refund/exchange/replacement is available (and local dealers do offer this). * I insist on detailed sales receipts (not just cash register tickets). * I inspect and play all purchases within 10 days. * I save receipts forever. * I keep Pioneer's customer service number current and handy. I buy Pioneer (of any variety) only because of Pioneer's reputation for standing behind their product. I have a separate article (LD#09) available on how to identify pressing plants and distributors. Regards, PO Box 248 Bob Niland Enterprise mailto:name@isp-name.domain Kansas which, due to spam, is: 67441-0248 USA rjn AT access DASH one DOT com Unless otherwise specifically stated expressing personal opinions and NOT speaking for any employer, client or Internet Service Provider.