Some quick answers from my memory below:
> -----Original Message-----
> From: Alan Tyson [SMTP:[EMAIL PROTECTED]]
> Sent: Wednesday, November 29, 2000 10:16 AM
> To: [EMAIL PROTECTED]
> Subject: Re: filmscanners: cd storage
>
> Dear Jerry,
>
> It would be fascinating to see the list, but even more
> interesting to read the details of the results. I assume the
> article's only available in Dutch, is it?
[Oostrom, Jerry] yes
> I hope they used very big sample sizes. I should expect the
> failure rates to be so low as to need samples of hundreds
> per brand. I should be most interested to hear what sort of
> failure rates they found. Did the article specify the rates?
> It would give us an idea of just how big a gamble we're
> taking with our image storage.
[Oostrom, Jerry] I suspect the rates are not that high. Have to look up the
article.
> Also, in my experience of writing & using CD-Rs, there's
> much more variation between drives than between discs.
> Faulty discs can be readable on some drives and not others.
[Oostrom, Jerry] They tested with at least three consumer drives. A philips
capable of 8x speed, an HP capable of 10x speed and a plextor capable of 12x
speed.
> So did they use some top class scientific equipment and
> actually measure the vital statistics of the written data?
> Or did they use retail consumer writing equipment for the
> tests, in which case how did they eliminate variation
> between drives?
[Oostrom, Jerry] They used equipment consumers would also be using.
> BTW....
>
> The data are in the chemically sensitive layer on the
> non-label (bottom) side, so a label will make no difference
> to UV exposure. The reflective metal layer already offers
> perfect protection from the top.
[Oostrom, Jerry] Perhaps for good ones. I've seen more than one disc
through which you could see light shine through. These were not perfectly
protected in my opinion. Anyway the magazine said nothing about the ceramic
protecting the disc (that was my extrapolation / hunch), but it said that
labels were a good way to protect the disc especially towards the outside
ring from UV light. The outside boundary of the disc was said to be
especially vulnerable to light. My interpretation: this will be true for CDs
not stored in total darkness, e.g. a spindle where the CDs are stored
vertically and the spindle casing is shine through plastic. Any 'perfect'
metal protection on one side of a disc will 'perfectly' reflect UV to the
other side of the neighboring disc. Do you agree this is a possibility?
[Oostrom, Jerry] Anyway, I don't think the test would have been done with
100s of CDs per series of a brand and expensive scientific equipment as the
magazine itself is targeted for the Netherlands (perhaps Belgium too, 2 tiny
countries) only, the magazine does not contain a lot of 3rd party commercial
advertising and the test seemed to be a national one (i.e. I thought the
results would only have been printed in the dutch version of the magazine).
That severely limits the amount of money they can devote to this test. But,
perhaps the results can still be used as an indication for which CDs to use.
And perhaps somebody from Germany noticed whether the same test appeared in
the Stiftungs Warentest (it's called roughly like that I believe). If that
is so, the targeted audience was much larger and chances are that the
resources devoted to the test were much larger then if it were only for the
ducth market.
Greetings,
Jerry.
