OK I'm sure in this aspect of the format technology I'm gonna sound like a total Luddite, but I'm uncomfortable with the notion of hard-coat. Not that it won't reduce scratches, but that long-term it remains clear, adhered, and stable.

I've never had luck with any scratch-resistant coating on my glasses (plastic or glass), and every time I get a new pair I'm told "this is different from what you had before"

I'm sure I'm going to have to go "neutral" sooner or later, both sides will have too many desirable titles to ignore, but believe it or not this is a major reservation for me.

Is "blu-ray rot" just total FUD, or have there been problems? Has this coating been tested on other sensitive optical material for extended periods? Also can BD disks be cleaned safely, and if so what with?

No experience with BD, but for any disc I always use a nice clean microfiber cloth. You can rub hard and they won't scratch. As for the hard coat chemistry changing over time, I guess that remains to be seen.

There is no such thing as "blu-ray rot". There was one bad batch of Prestige discs pressed with either an 'experimental method used' (Amir's description) or a contaminant in the mix (Paid's description); but either way both agree their is no fundamental design flaw; just a QC issue with one title.

As far a the glasses thing; I agree; I've had the same experience. This BD hardcoat is different, though; my experience thus far (and from reading threads of others, even rental discs) suggests this is a major improvement over DVD & HD DVD. I have had zero, and I mean zero, playability issues with any of the 30 or so titles I've played; no freezes, no skips, no lockups, fast startups, etc (PS3). I think the user experience for BD is excellent, exceeding DVD IMO (note that this is for PS3; I'm aware that their have been issues with some of the standalones handling BD-J titles, etc).

I work for a company that use both a dip hard coating and a vacuum deposited anti-reflection coating on spectacle lenses.

While I'm sure the coatings are different the science isn't.

They should hold up fine as long as you don't wash them in gasoline:)

I ran across this conversation in posts over on the Classic Horror Film Board the other day and thought about bringing it up here, but dreaded the inevitable flames and bakc and forth- however since you already broached the subject....
I don't have any familiarity with the two posters here, since I've only been lurking there a short time. I also don't claim to understand the science or tech involved, but it sounds like they do.
it does give me a bit of pause about building up too large a Bd collection...but then rot or some unforseen degredation could hit my HD DVDs too so who can say


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When I first saw microscopic representations of the data layer on the two formats, Blu-ray scared me. Those tiny data pits sitting near the surface are an invitation to disaster. As for scratch resistant coatings...I ran the coatings department at an aerospace company for over 5 years and I've NEVER seen a functioning PERMANENT coating in my life. If you coat plastic, that coat will will eventually fail.


Every time I would suggest a coating on plastic (which is probably just a glorified urethane) was a bad idea, I was always told that I was spreading FUD. Truth be told, like yourself I'm highly dubious. If it doesn't full on peel, it could easily go yellow or cloud. Plastic doesn't breath, and it has no "tooth" so it's really hard to find things that will stick permanently. Look how dye-casting and electro-plating flakes in time. There's a reason why most plastics are intrinsically tinted rather than painted. I'm just speculating, but I think it's a healthy skepticism.

HD DVDs, DVDs, and CDs, are standing the test of time quite well and have proven themselves. I don't think SONY gives a fart about the long-term stability of anything, they're engineers not preservationists.

I am format neutral. Hoping HD-DVD wins the war due to combo disc for the kids and region free love, but I have had WAY more software problems with HD-DVD than blu-ray. I own over 20 br's and have rented countless. Only had one bad disc and it was a rental. Every time I buy an HD-DVD combo,I cross my fingers the first time I put it in the drive. I won't even buy HD-DVD's used from amazon or ebay due to this.

So I think the hard coat works, but has nothing to due with iffy combo QC, the HD-DVD's seem to be more affected by small scratches than Cd's or dvds's (Netflix experiences). I wish the formats could mash up and make like an HD-Ray that holds 50 GB has WORKING combo's with hard coats and are region free.

It's the whole time factor that troubles me, not that it has issues right now, I'd hope not after a couple years. It's the 6...8...10 year outlook that worries me.

For a sense of balance I will also state that combo longevity is also a concern, I now have flipper DVDs that are close to 10 years old and play fine, but the aren't the more problematic DVD-18's, and they don't have data pits as small as HD DVD and the even smaller BD format.

I collected LDs and had something like a 18%-20% rot-rate before I sold my collection. Many LD collector's claimed the fail rate was a lot lower than I experienced. However, I know darn well they weren't looking at the 100's of disks they owned on a regular basis.

I was teaching a film class at he time and constantly pulling titles for reference material, and constantly reviewing my collection.

While there are no long term tests of the "hard coat" they have been making these kinds of discs for 25 years and have a good grasp of the technology.

There is an interesting YouTube video which test the hard coat. He uses talledega nights (Best use for that BR!) and absolutely tortures the thing and it played after going thru some major hell (Finally killed it with matches). Search Blu-Ray, Talledega Nights, test,PS3 and you should find it. Pretty interesting and funny.

OK I'm sure in this aspect of the format technology I'm gonna sound like a total Luddite, but I'm uncomfortable with the notion of hard-coat. Not that it won't reduce scratches, but that long-term it remains clear, adhered, and stable.

I don't think that there is much, if any, comfort in using a hard coat on Blu-ray discs. Blu-ray discs still have a significant, potentially fatal design flaw: data on a Blu-ray disc is only 0.1 mm from the surface, whereas with HD DVD the data is six times deeper at 0.6 mm so the focal point is farther from the surface.

This point should not be lost. Don Diotte, CEO of Venmill Industries said the following in The Winnipeg Free Press, Page E5, Nov 15, 2006:

"Blu-ray may hold more data than HD-DVD disks, but there is a trade-off. To fit more information on the disk, Sony had to reduce the thickness of the protective coating. Consequently, the discs are much more vulnerable to scratches... In the USA there's a billion dollar buy-sell industry around computer games. I do not know how they're going to face the reality that Blu-Ray is an unrepairable format."

So there you have it. Not only is the longterm viability of this hard coat in question, the scratch resistant coating (which is a necessity, not a feature) on Blu-ray discs can still scratch regardless and when they do they are much more vulnerable to scratches and will skip, stutter, freeze and outright ruin the disc. Once this happens, you're out of luck since the disc cannot be repaired. With HD DVD, the same scratch will either not affect playback because the laser does not have to focus so close to the surface, or if playback is affected HD DVD can be fixed very easily just like a regular CD or DVD. Blu-ray disc was originally designed to be inside a caddy, and they should have kept it that way.

There is an interesting YouTube video which test the hard coat. He uses talledega nights (Best use for that BR!) and absolutely tortures the thing and it played after going thru some major hell (Finally killed it with matches). Search Blu-Ray, Talledega Nights, test,PS3 and you should find it. Pretty interesting and funny.

Some Blu-ray supporters love to point to this youtube video of a BD "torture test" where someone appears to damage a Blu-ray disc a number of times only to see it work "perfectly" after each "test". I'm dumbfounded that people still point to this video. The only thing that "test" proves is that the tester doesn't even know how to conduct a proper test. Just because the disc was recognized as a Blu-ray disc and appeared to start loading up does not mean that it would not have stuttered or stopped playing all together 5 or 10 seconds after starting the movie, assuming that it would have even got to the menu. Why did we not even see the menu load up? Or the movie playing? Why did the tester fail to state that the movie played back flawlessly from beginning to end after each "test"? The truth of the matter is that it would have been laughed at and tossed out as inadmissible in any court of law. It was nothing more than one fanboy's nonsensical attempt to demonstrate the 'indestructible' nature of a Blu-ray. Anybody who falls for that video will likely fall for anything.

Still, other Blu-ray supporters who just so happen to be "neutral" love to suggest that every single HD DVD rental they've tried were scratched up beyond recognition and wouldn't play. Either they're lying through their teeth (and probably rent HD DVD just to intentionally scratch a few) or they're exaggerating to no end in trying to make Blu-ray discs sound impervious to problems. Here are some recent threads from the Blu-ray software forum of problems that users have been having:

Small scratches = big time skipping (http://www.avsforum.com/avs-vb/showthread.php?p=11244474#post11244474)
Netflix vs Blockbuster re: cracked discs (http://www.avsforum.com/avs-vb/showthread.php?t=881139)
Is Netflix resurfaceing Blu-Rays the same way DVD's are resurfaced? (http://www.avsforum.com/avs-vb/showthread.php?t=878527)
Problem with the Searchers (http://www.avsforum.com/avs-vb/showthread.php?t=868337)
Netflix: No comment on Blu-Ray resurfacing (http://www.avsforum.com/avs-vb/showthread.php?t=879220)
Two damaged Stargate Bluray disks in a row from Netflix (http://www.avsforum.com/avs-vb/showthread.php?t=870646)
HellBoy Playback Problems (http://www.avsforum.com/avs-vb/showthread.php?t=869968)

Bottom line is that no format is without issue. However, if I were to choose between a format that could be repaired and one that could not, I choose the format that I can fix if the need arises. And that choice is HD DVD.