Talk:CD-R

message: -How come the normal CDs with things already written on them are all smooth on the "burned surface", when CD-Rs have a sharp mark of where the writing has ended?(Henningklevjer 17:38, 20 April 2006 (UTC)
replies: text: normal CDs are reflective all over, they just reflect to a slightly different place depending on if a site is pit or non-pit so to the human eye under normal lighting they look even. CD-Rs use a reflective layer into which dark marks are burnt and while the individual marks are still too small to see thier effect on the average color is noticeable. Plugwash 02:03, 9 July 2006 (UTC)
thread_title: CD-Rs and 'normal' CDs

message: it isn't burning pits into the dye; it's changing the color of the dye to make it less reflective, right? - Omegatron 05:30, Jan 15, 2005 (UTC)
The dye isn't reflective... the reflective layer (usually silver or a silver alloy) is.  You don't burn pits in a CD-R, you burn dark spots in the dye layer.  These dark spots absorb the light from the laser in the CD player's pickup more than the unexposed areas of dye, and so the reflected light and the resulting signal goes down whenever the read laser encounters a burned mark.  The effect on the returning laser signal is similar to what happens on a replicated CD... similar, but different.  
A replicated CD has a track of pits that are molded into the disc.  These pits are molded in clear plastic, and they are coated with a reflective layer of aluminum.  Although aluminum has lower reflectivity than silver, there is no dye layer on a replicated CD, so very little laser light is absorbed.  When the focused laser spot of the CD player's pickup encounters a pit the light is diffracted, and the reflected light is greatly reduced (and the resulting signal voltage goes down).
So, while CD-Rs have burned marks that absorb the light and CDs have pits that diffract the light, the effect is that recorded CD-Rs emulate replicated CDs, which is what they were designed to do.  
Actually, a replicated CD has pits molded into it, but it is read from the underside through the 1.2 mm thick polycarbonate disc, so the laser is actually focused on a track of bumps.  But the diffraction is the same.  Now, some people will tell you that the optical effect is the phase cancellation of the light being reflected from the bottom of the pit (top of the bump), versus the light that is reflected from the land areas around the pit (since the read laser spot is twice as wide as the pits are), but at these geometries the physics can be understood as pure diffraction.  Keep in mind that the pit geometries are a fraction of the laser wavelength. Tvaughan1 21:27, 18 August 2006 (UTC)
thread_title:  burning pits? 

message: Compatibility of CD-R and conventional read-only discs, CD and CD-ROM, is a miraculous achievement which was made possible by the dye materials developed by Taiyo Yuden.
I like Taiyo Yuden, too, but I don't think we should ascribe divine powers to them. Perhaps it was merely a wondrous achievement? Stunning, maybe? Gob-stopping?
--68.41.122.213 11:02, 13 December 2005 (UTC)
thread_title:  Mene, mene, tekel, upharsin? 

message: http://tech.msn.com/howto/article.aspx?cp-documentid=23697
From the above article:
The problem is material degradation. Optical discs commonly used for burning, such as CD-R and CD-RW, have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data "shifting" on the surface and thus becoming unreadable to the laser beam.
"Many of the cheap burnable CDs available at discount stores have a life span of around two years," Gerecke says. "Some of the better-quality discs offer a longer life span, of a maximum of five years."
Distinguishing high-quality burnable CDs from low-quality discs is difficult, he says, because few vendors use life span as a selling point.
From the Wiki page:
Burned CD-Rs suffer from material degradation, just like most writeable media. Optical discs commonly used for burning, such CD-R and CD-RW have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data "shifting" on the surface and thus becoming unreadable to the laser beam.
Many of the cheap burnable CDs available at discount stores have a life span of around two years. Some of the higher quality discs offer a longer life span, of a maximum of five years. Distinguishing high-quality burnable CDs from low-quality discs is difficult, because few vendors use life span as a selling point.
65.118.253.68 18:09, 18 January 2006 (UTC)
replies: text: Possible? That's outright plagiarism. Plus, that is an opinion. Listen to the most recent This Week In Tech podcast (#39), where they discuss how some CDs from 1988 still work perfectly. --worthawholebean talkcontribs 01:24, 25 January 2006 (UTC)

text: If the quality of CDr is in the top 10 percent you should expect the cd to last ONE HUNDRED years without degradation. Anyone who says the max lifespan is 5 years is talking out their ass. Most of the CDrs I burnt in the 90s still work. However saying the lowest quality ones may only last 2 years or less sounds possible. Avoid bottom of the barrel blank cds. For example getting cdrs at a dollar store may be a mistake.  — Preceding unsigned comment added by 70.67.123.123 (talk) 02:29, 13 November 2018 (UTC)
thread_title:  Possible plagiarism 

message: calling something a miraculous achievement is certainly POV - a miracle is about as pov as you can get. 65.35.93.97 15:09, 20 February 2006 (UTC)
replies: text: I looked in the thesaurus briefly, but I thought it would be best just to drop the adjective and rewrite the sentence. Rhobite 02:59, 28 February 2006 (UTC)
thread_title:  Miraculous?!?!? 

message: I've used simple liquid disk washing detergent for 10 yrs.  Cleans off sticky stuff, oils, and dirt.  I always pat dry with a clean soft cloth.
. . . regarding "use a circular motion to remove all the toothpaste"; why circular when the previous instructions were to move in a radial direction ? - Sue 08:40, 14 August 2006 (UTC)
thread_title:  Cleaning CDs 

message: "They use Eight-to-Fourteen Modulation, CIRC error correction plus the third error correction layer defined for CD-ROM. The first CD-Rs were produced in 1988"
CIRC linked to a disambiguation-page, so I changed the target page to the appropriate one, namely http://en.wikipedia.org/wiki/Cross-Interleaved_Reed-Solomon_Coding. 62.238.92.181 14:51, 18 April 2006 (UTC)
thread_title:  CIRC Link 

message: is the above method of cleaning likely to damage a CD? it certainly seems effective at getting the grime off them. Plugwash 11:59, 22 May 2006 (UTC)
thread_title:  spit and a corner of my T shirt 

message: :non-standard CD-Rs are available with capacities of 79 minutes, 59 seconds and 74 frames (marketed as 80 minuites) /736,966,656 bytes (702 MiB), which they achieve by slightly exceeding the tolerances specified in the Orange Book CD-R/CD-RW standards.
My understanding was that most 80 minute CD-Rs in fact fully complied with the standard. The standard specified large tolerances due to the manufacturing tech at the time but as this improved, it became possible to make 80 minutes CD-Rs which fully complied with the standard but were obviously at the upper end of the tolerances. Perhaps what I've heard is wrong and tolerances and manufacturing tech doesn't actually allow 80 minutes CD-Rs to be produced which fully comply or they're mostly not fully compliant but if there is some truth to this story, e.g. tolerances and tech allow up to 78 minute fully complaint CDRs, we should make it clear this idea clear, that the tolerances were rather loose and better manufacturing tech allowed CD-Rs to be produced which only marginally broke the tolerances... Nil Einne 11:59, 26 May 2006 (UTC)
replies: text: Nil is correct... 80 minute CD-Rs can be manufactured when all relevant parameters are at the edge of the specification (program start radius, program end radius, track pitch and linear velocity).  If the accuracy of the LaserBeam Recorder (LBR) that cuts the glass master is good, pushing a CD-R to the edge of the specification isn't a problem at all.  DVDs use a track pitch that is half of CD.  The theoretical maximum capacity of a CD-ROM or CD-R is about 79 minutes and 58 seconds, or 702 MB (I hate MiB... please don't subject us to it... a Megabyte is 2^20 bytes). Tvaughan1 22:17, 17 August 2006 (UTC)
replies: text: I remember one player that would not play 80 minuite CDRs but would play 74 min ones fine, it was years ago though (when burners were arround the £100 mark) and the player was a pretty old one even then (I don't know the exact make or model, it didn't belong to me). Plugwash (talk) 02:48, 24 January 2009 (UTC)
thread_title:  80 minute CD-Rs 

message: The lede ends with this: "The CD-R retains all the abilities of the CD standard but adds the functionality of being able to store either music or data." I have plenty of regular CDs that contain music and data. Isn't the real distinguishing characteristic of CD-Rs that music and data can be recorded onto them? --Rob Kennedy 07:27, 7 July 2006 (UTC)
replies: text: No, that's nonsense. The physical variant of a CD has nothing to do with what can be stored on it. Pressed CDs containing music and data are/were just rather uncommon. Some audio CD players would try to play the data track which can damage the speakers and it sounds awful anyway. Game CDs often contain audio CD tracks especially older consoles used this. --82.141.58.211 18:39, 30 July 2006 (UTC)
replies: text: Are you saying that my question is nonsense, or that the sentence I’m asking about is nonsense and should be removed or reworded? --Rob Kennedy 01:41, 6 August 2006 (UTC)
thread_title:  Lede 

message: Could someone add a section describing 'audio CD-R'? In the UK at least, most consumer audio cd writers are restricted to this type of disc so that a levy can be paid to the music publishers. Many users are confused about this.--137.205.146.206 09:20, 3 August 2006 (UTC)
replies: text: What in the world are you talking about? You're the first person I've ever read to bring this up.Coffee5binky (talk) 16:26, 10 December 2009 (UTC)
thread_title:  audio CD-R 

message: According to a Maxell press release from 2002, burning CDs at or faster than 52X carries with it some risk.
If this is correct, maybe it should be incorporated into this article, somehow?  Looking at Maxell's webpage, I see that the fastest CD-Rs they produce are still 48X ones... TerraFrost 17:04, 27 November 2006 (UTC)
thread_title:  max burning limits? 

message: There is nothing in article about any countries taxing CD-R as a way to combat music piracy.  Germany, France, Italy, The Netherlands and Spain all have CD-R taxes and Canada is considering it.  Jon513 14:10, 30 November 2006 (UTC)
replies: text: According to , Canada has been taxing CD-Rs as early as 2002 TerraFrost 16:21, 30 November 2006 (UTC)
replies: text: Don't know about the others, but both Germany and the Netherlands impose a levy on audio recordable media that is used to pay the recording artists.  Once you have bought such media, you are entitled to record on it anything you like.  Although Audio-CD-Rs have such a levy (and are coded as such) ordinary CD-Rs do not and are consequently cheaper.  Audio CD recorders will only record to specific Audio-CD-Rs, but computer drives will record audio to pretty well anything, and if Audio CD-Rs are not used for audio, then piracy is the name of the game.  I believe video media is treated the same way, but I have not seen specific 'Video DVD-Rs' only the regular kind, but it may be that the levy is imposed on a blanket basis. 109.145.22.224 (talk) 15:51, 20 April 2012 (UTC)
thread_title:  taxes 

message: "most markers can bleed-through the CD/DVD and destroy your data"
The article on disk care linked in this section contains related product advertisement ("Maxell Disc Writer Pen"). I am not sure if it would be considered indirect advertising. 124.168.184.54 10:25, 28 January 2007 (UTC)
thread_title:  Optimal storage conditions and expected lifespan 

message: I rewrote the paragraph on the writing process. Got rid of the repetition of the the term "burn"; removed phrase calling the dye layer "magnetic". I intentionally left it vague as to whether heating the dye causes a lowering or a raising of the reflectivity. Does anyone know for certain which it is? Spiel496 04:22, 17 February 2007 (UTC)
thread_title:  Writing Process 

message: In all the incredible techy detail here, everyone's rather overlooked the retail history of the CD-R format. All I can tell from this article is that the spec was published in 1988. Please someone expand the History section before adding even more geeky stuff. (And I say that as someone really interested in the geeky stuff!) 86.143.52.241 02:27, 3 June 2007 (UTC)
replies: text: I personally remember recordable CDs of some form (though perhaps not 100% "Orange Book" compliant implementations)to be available to the general public since 1991, at least. The downside was that the recorders were usually external, bulky units with parallel or SCSI or custom interfaces, and their usability was nowhere near close to that offered by modern CD-burning tools: they were meant mostly for traditional data backup, and even the file systems or pit/land encoding methods could differ greatly between manufacturers, rendering these "CD-R" largely incompatible with each other. The mainstream and affordable CD-R with ISO-standard file systems and without weird recording quirks became widely available only after 1994 or so. EpiVictor 21:00, 31 August 2007 (UTC)
replies: text: 1989's License to Kill James Bond movies has Felix using a LaserDisc recorder that also records to CD-Rs, which he hides behind a picture. For consumers, 1987 is a fair estimate, if you wanted to pay like $25,000 (guessing) for the drive and (guessing again) $250 a disc. Despite when if may come onto the market, CD writers may have come about around 1995 or so at prices people were willing to pay. (Again, guessing, but all my old PC World issues don't mention CD writers until 1995.) Coffee5binky (talk) 16:31, 10 December 2009 (UTC)
replies: text: I doubt that a cinematic entertainment is an adequate citation.  The main problem here is that: if a LaserDisc recorder existed (which it didn't), it was a totally different technology to CD (i.e. the former is analogue, the latter is digital - for starters!).  109.145.22.224 (talk) 15:54, 20 April 2012 (UTC)
thread_title:  When did CD-Rs become generally available? 

message: I'd like to add this information to the article, but I'm not sure how to do it.  I will leave it up to someone more experienced than I.  The following comes from Janis Ian, a former singer from the era of the 60s and 70s:
"Several years ago the music industry reached an agreement with CD manufacturers to receive a royalty on blank, recordable CDs to compensate for the effects of copying music.  The recording industry is receiving a royalty for the "Audio" CD so that it can be used for copying music, taking that money, and then turning around and complaining that the CD is being used to make "unauthorized" copies. Now what is up with that?  -  http://www.janisian.com/article-internet_debacle.html and http://www.janisian.com/articles-perfsong/Fallout%20-%20rev%2011-23-05.pdf   -  Theaveng 17:44, 31 August 2007 (UTC)
replies: text: This is the old story of the CD Audio "for consumer" disks. Read the CDR FAQ for more info on that. Considering how this was as stopgap measure that only seriously affects stand-alone audio CD recorders (not computer CD burners), it's hardly a case of the industry making much money out of illegally copied music. Quite the opposite, a standalone CD Audio recorder is actually the less likely tool for a true music pirate to operate. Surely those "CD Audio" recordables aren't the first choice for music pirates either, due to cost. Pirates just buy the cheapest general purpose CD-R and are perfectly happy with those, the royalty system is hardly paying itself. EpiVictor 21:01, 31 August 2007 (UTC)
thread_title:  Record Companies receives money from illegally-burned Music CD-Rs 

message: The numbers in the column "Write time for 80 minute/700 MB CD-R" appear to be simply 80 minutes divided by the speed.  Is there evidence to support these numbers?  It is my understanding that above about 16x the discs are spun at constant angular velocity, and that the read/write speeds then refer to the speed at the outer radii.  In other words, 52x is achieved only at the outer edge of the disc; the inner radii will be written at the same RPM, which works out to about 20x.  So you're not going to be able to write a whole disc in 80/52 minutes.  Does anyone know for sure?  Spiel496 (talk) 18:10, 14 January 2008 (UTC)
replies: text: You are right, all CD-R wriers I know use Zone-LV beginning at 24x speed. So it's not possible to write 700MB in 1.5 minutes. The time span at which 24x speed recording takes place is much larger than the time span of 52x speed recording. --80.134.6.41 (talk) 09:48, 1 June 2008 (UTC)
thread_title: Bogus speed table?

message: Guys I saw a French news in Sydney, FRANCE 20HR of 03/03/2008 saying that CD only last as much as 10 years! The research was conducted and they concluded from the word of the researcher of Jacques Perdereau that it can only last as much as 5 (30% to 50% damage)!!!
Results seen: FRANCE 20HR of 03/03/2008
I cannot fully understand the research organization... But it is true! 
I mean, it is quite shocking... Can we actually upload videos!?
Anyone target other proof will be helpful. If you would like to watch the original broadcast of the news in French, you are more then welcome to visit http://www.ina.fr/video/3571726001/20-heures-emission-du-3-mars-2008.fr.html
But of course, it is in French. You may also find the dialogue in text format below the page as of 26 Jul 2010. (D. Lau (talk) 13:33, 26 July 2010 (UTC)
replies: text: I offer my own experiences, since I've been in computers since 1980 and using CDs and CD-Rs since the late 1980s. I have many discs over a decade to a decade and half old, and I have some really old CD-Rs from the late 1980s that I can still access data from. This "life of the disc" crap is the same stuff I heard about regular CDs in the 1980s, that the plastic would wear off after 8 years. Guess what? IT DOESN'T! So here's the deal: If you use cheapo discs with cheapo burners, expect problems. Some discs will develop bubbles on the burn surface because of cheapo techniques. If you use a good quality drive with good quality discs, then your data will last. That's all. Coffee5binky (talk) 16:42, 10 December 2009 (UTC)
replies: text: If you have nothing friendly to share, then it is best to remain quiet. Beside, I check the source, it was on the French News 20 H. News are news. They can be subjective...or misleading. Flowright138 (talk) 13:36, 26 July 2010 (UTC)
thread_title:  CD Life! 

message: My first CD-R drive in the mid-1990s used a CD caddy.  Any idea what the purpose of this was?  The article needs a mention of this if it was a mass market idea. -Rolypolyman (talk) 18:05, 7 September 2008 (UTC)
replies: text: The low importance of CD caddies might be answered in this article simply by adding a link to Caddy (hardware)#Optical media caddy. Binksternet (talk) 19:35, 7 September 2008 (UTC)
thread_title:  CD caddies 

message: If anybody reverts my edit about the dark/light areas of a disc, they are wrong to do so. Every CD-R I have burned always have darkened data areas.  —Preceding unsigned comment added by Shane91c (talk • contribs) 22:03, 23 January 2009 (UTC)
replies: text: Well, wrong or not, I rewrote the paragraph, removing claims about whether the writing darkens or lightens the disc.  To me, the written area looks darker in specular reflection.  But it also scatters more light, so it can appear brighter depending on the lighting. Spiel496 (talk) 15:09, 24 January 2009 (UTC)
thread_title:  Disc Usage Estimation 

message: Hi People! I am having a lot of used CD-R/DVD-R. any ideal what should do to recycle the plastic to save the world? Thanks and Regards.  —Preceding unsigned comment added by Angelicalchin (talk • contribs) 18:16, 18 February 2010 (UTC)
thread_title:  Recycle 

message: An additional form of security disposal is to skim the label side of the CD in a lathe.  Grip lightly in the 3-jaw chuck and run at high speed.  A sharp knife tool will skim the surface and reflecting layer off.  The only downside is that the swarf is incredibly light and gets everywhere.  I'm afraid this falls foul of WP:NOR unless someone can find a citation somewhere. Martin of Sheffield (talk) 18:02, 24 November 2011 (UTC)
thread_title:  Disposal 

message: The article says 1988, but Rainbow_Books#Orange_Book_(1990) says 1990 for the orange book. I suppose it depends on the exact meaning of release.  Kodak PhotoCD came out, as well as I know, in 1990. Presumably much development was done before the official release. Gah4 (talk) 10:07, 7 February 2020 (UTC)
thread_title:  release