Re: [ARSCLIST] Testing DVDs

[Jerome Hartke <jhartke@xxxxxxxxxxxx>]

Based on testing for our clients, I believe that you are pursuing the wrong
quality indicators. "Too cumbersome and time-consuming" suggests that you
wish an easy answer to a complex question. Such answers invariably lead to
misguided efforts, a false sense of security, and unsatisfactory results.

Jerry Hartke
Media Sciences, Inc.
www.mscience.com

> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx] On Behalf Of Peter@xxxxxxxxxxxxx
> Sent: Thursday, June 02, 2005 7:43 PM
> To: ARSCLIST@xxxxxxxxxxxx
> Subject: Re: [ARSCLIST] Testing DVDs
>
> I will be attending the AES/ISO meeting of the Technical Commission on
> Tape
> and Disc preservation this coming week.  We have been discussing ways of
> testing DVD's and it is a subject that is part of next week's agenda.  So
> far, it is unfortunately true that the testing methods developed and
> recommended are somewhat too cumbersome and time-consuming to be widely
> practical.  If we review any documents that offer reasonable alternatives,
> I
> will report such to the list.
>
> One of the primary failure mechanisms that needs more testing is
> delamination.  In my opinion, from review of the available data, there is
> not enough reliable information on the stability and reactive properties
> of
> the glue used to bond the layers together.  If someone has a good, quick
> way
> to test the glue stability, I would be pleased to pass it on to the
> Commission.
>
> One of the problems encountered (again, in my opinion) is that testing for
> new mediums tends to mimic the tests for previous mediums.  Accelerated
> aging tests for recordable sound media were initially developed to try and
> test binder hydrolysis.  Discs are a very different animal than tape.
> Polycarbonate disc surfaces do not hydrolyze like polyester binder in
> tape.
> On the other hand, reflective mediums in Discs can oxidize while ferric
> oxide recording pigments in older tape don't.  Again, the binder mechanism
> on tape is integral to the entire recording layer while Discs are actually
> held together with an added layer of glue.
>
> It is quite possible that we need to seriously re-think the testing
> parameters and methods for Discs.  Again, if anyone has some suggestions,
> I
> would be glad to pass them along.
>
>
> Peter Brothers
> President
> SPECS BROS., LLC
> (201) 440-6589
> www.specsbros.com
>
> Restoration and Disaster Recovery Service Since 1983
>
> > -----Original Message-----
> > From: Association for Recorded Sound Discussion List
> > [mailto:ARSCLIST@xxxxxxx]On Behalf Of seva
> > Sent: Thursday, June 02, 2005 9:38 AM
> > To: ARSCLIST@xxxxxxxxxxxx
> > Subject: Re: [ARSCLIST] Testing DVDs
> >
> >
> > i think that querying Mitsui itself would yield more information. they
> > have a sterling reputation and i'm sure would have no intention to
> > launch the gold DVDs without serious advanced aging tests of their
> own...
> >
> >
> > David Lewiston wrote:
> >
> > >So there are plenty of brilliant comments, but no practical
> > suggestions for
> > >doing a quick and dirty test?
> > >
> > >Salutations, David L
> > >
> > >
> > >----- Original Message -----
> > >From: "Nigel Champion (ARTS ANT)" <n.champion@xxxxxxxxxxxxxx>
> > >To: "David Lewiston" <david.lewiston@xxxxxxxxxxx>
> > >Sent: June 01, 2005 4:35 PM
> > >Subject: RE: [ARSCLIST] Gold DVD-Rs
> > >
> > >
> > >Then you need to repeatedly insert and remove the DVD-R from its' case.
> > >This is to find how long it takes to separate the two polycarbonate
> > >layers of the DVD!
> > >
> > >Regards
> > >Nigel
> > >
> > >
> > >
> >
> > --
> > salutations,
> > seva
> >
> > www.soundcurrent.com
> > || | |  |   |     |        |             |                     |
> >
> > Things are not what they seem to be; nor are they otherwise.
> >    -- Lankavatara Sutra
> >
> >