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Post by John Green on Mar 19, 2014 10:55:29 GMT
'Disc rot'.What a pain in the lumbar region.
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RWels
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Post by RWels on Mar 19, 2014 10:55:54 GMT
Disc rot first occured in laserdiscs.
I had a few discs (all from 1 guy) that became unreadable already after what, 2 years? Today I try to have copies on discs and on hard disk drive.
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RWels
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Post by RWels on Mar 19, 2014 11:02:19 GMT
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Post by Dan S on Mar 19, 2014 23:30:11 GMT
BTW What's the betting that most DVD-Rs will be suffering from vinegar syndrome within about 15 years? Vinegar syndrome only affects acetate film, not DVDs. There is a condition known as Disc Rot which affects CDs and DVDs, which is worth bearing in mind if you have a large collection of DVD-Rs. Personally, I would advise making back-up images of any DVDs you burn and storing them on an external hard drive. hopefully you won't be unlucky enough that your disc rots and your hard drive fails at the same time. Another option would be to consider burning two copies of every disc, using different brands of blank media, and checking the discs regularly. There's also "data fade" where a hard drive (disconnected from a pc and stored somewhere safely) will later be found to be unreadable because the data (or parts of it) has faded away. To prevent that from happening it's recommend the information be rewritten every <10 years, the easiest way is to recopy the data onto another drive. I hope the BBC have measures in place to prevent things being lost through disc rot, data fade, etc.
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Post by David Buck on Mar 19, 2014 23:50:56 GMT
I hope the BBC have measures in place to prevent things being lost through disc rot, data fade, etc. One of the interesting comments that came out of the panel discussion at the last MBW was that the BBC are now onto the third or fourth version of the latest digital tapes as each successive generation of them has failed, there was no mention of programmes being lost so I assume they either have two archived copies of everything or the raw data is still exportable from them even if they won't play back properly, Can anyone remember what format it was they mentioned or knows the issue from their own experience? - It's post the D2, D3 issue and I think it was mentioned that Betacam was whilst technically inferior far more stable.
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Deleted
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Post by Deleted on Mar 20, 2014 11:05:47 GMT
Yes, it was commented that Digi-beta has been the most reliable digital format overall. I think it was one of the early formats (possibly D2?) which they said was found to be unreliable, although I'm not certain about this. I hope the archives are covering themselves properly on these matters!
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Post by Lionel (Coop) Cooper on Mar 20, 2014 12:16:51 GMT
If by any chance that there is the 2nd copy I hope that someone will still try and recover what they can from the damaged one as it would be good practice in case something else turns up that needs rescuing
very sad seeing it in this condition.
does anyone know how long it has taken to get into this mess ? ie if it was found 5 or 10 years ago would it have been ok
prob not an easy question to answer as too many variables
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Post by Alex Dering on Mar 20, 2014 13:19:55 GMT
30 years ago, beta was a viable format. Picture this scenario: Cleaning out a spare room at recently departed Uncle Fred's, you come across a box of beta tapes. "I wonder what's on them?"
You make a note to see if you can find Fred's beta player. You can't. Maybe/maybe not, there's writing on the labels: Feast of Steven, Mission to the Unknown, Romans, Myth Makers, Faceless Ones, Highlanders. You make the obvious conclusion. You've found Uncle's porn stash. "Sigh," you sigh. "He used to bounce me on the knee and tell me all those wonderful stories about those evil Dalek things from the planet Skaro. I wonder where he came up with that stuff. Now I have to burn his porn box. There's just so much to do here, I can't go looking for a machine to see what's on these other unlabeled tapes. Power of the D----s? It's smudged. But I think I know what that last six-letter word is. Good God. Uncle Fred had one wild side to him."
With all the effort to find tapes and films, is anyone making an effort to gather the equipment (and software) necessary to read these formats that are going/have gone extinct?
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Post by Lionel (Coop) Cooper on Mar 20, 2014 14:34:15 GMT
ive still got a load of beta, n1700 and grundig svr tapes to go through when I can get round to repairing the vcrs ! hope my tapes are still ok
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Post by David Robinson on Mar 23, 2014 17:13:18 GMT
I cant tell Paul what to do this.. but this is what i would do if i was in his situation. I would first have a heart to heart talk with Phil to determine if this is the only known print. I would guess they already know the answer to this and as to whether any other material has been recovered. No smoke without fire in this case I reckon!
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Post by Sue Butcher on Mar 25, 2014 0:21:43 GMT
At the risk of sounding trite, don't give up on this one! We may not have the technology now, but perhaps one day it will be possible to 'read' the image on the film without unrolling it. From the Wikipedia page on the Herculaneum papyri, it seems that techniques are being developed to read these badly-charred papyri without opening them first: 'In 2009, two intact Herculaneum papyri housed in the collections of the Institute de France in Paris were imaged using x-ray micro-computed tomography (micro-CT)... The internal structure of the rolls was revealed to be extremely compact and convoluted, defeating the automatic unwrapping computer algorithms that the team had developed. Manual examination of small segments of the internal structure of the rolls proved more successful, revealing the individual fibres of the papyrus. Unfortunately, no ink was visible on any of the small samples imaged, probably because carbon-based black inks had been used in antiquity, which have a much lower contrast to the blackened papyrus than inks with metallic bases. Progress with this promising technique thus most likely depends on the development of higher resolution micro-CT scanners so that computer algorithms can be created that will unwrap rolls automatically. A method is also needed to increase the contrast between the carbon-based ink and the charred papyrus.' It's quite a jump from a papyrus to a film, I know. But who knows. Maybe in the future we'll have phones with cameras and driverless cars... ;-) Silver would show against acetate. Easy to "unwind", too. Try it if it's not too expensive!
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Post by markboulton on Mar 25, 2014 22:14:22 GMT
D2 was indeed the flaky format. I remember even at the time when it was "the" format, c. 1992-96, tracking errors were quite plentiful to spot on-air - repeat showings suffering from total tracking breakdowns on an all too-regular basis (particularly when I was watching on Carlton/LWT). In fact, nearly every LWT show I ever saw in that timeframe had sparkly distortion over two bands across the picture - not easily spotted, admittedly, and not a major problem at the time - but it was clear to me these errors would only get worse in a very few years, with the control tracks seemingly not standing up to repeated playbacks.
Just about every show made in the "D2 years" that I have seen repeated on channels such a GOLD, Dave, Challenge etc. have all seemed to come from Beta SP dubs.
Sorry to go O/T again, if any further comes from this perhaps a new thread should be started. Just wanted to answer the question above.
(Incidentally, DATs also have suffered badly since their heyday in the 80s. It's very rare to ever find one that tracks reliably all the way through - or even for any more than a minute or so at a time - although that could also be a function of the players too.)
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Post by markboulton on Jul 4, 2014 20:48:08 GMT
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Post by Stephen Byers on Jul 8, 2014 0:09:21 GMT
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Post by markboulton on Jul 8, 2014 0:33:24 GMT
Except in the case of the print in question, there's no way they'd be able to leap to those stages! No siree! The DW prints in that clip were in beautiful nick by comparison.
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