Natalie,
There might be some 'dedicated' glass plate scanners available,
however I have not come across them myself. I suspect that they
might be rather expensive if they have been built specially for this
task.
However I don't think they are really necessary and many good quality
flatbed scanners with a transparency hood can easily be set up to
safely scan glass plates to a high quality. Or indeed, a digital
camera can easily be used to give high quality results at a decent
speed.
There are two basic designs of flatbed transparency scanner.
The first type use a 'hood' which contains a light source that shines
through the transparency/glass plate and down onto the ccd.
The second have a 'slot' where the transparency/glass plate can be
placed into a mount and then inserted into the body of the scanner
between the light source and the ccd. Examples of these would
include the Agfa DuoScan range.
This second kind of scanner 'could' be used for scanning glass
plates....however it would not be my first choice and I would be
interested in hearing from anyone who had used this kind of scanner
with success. My worries would be the challenge of creating a safe
support for the plate, whilst within the scanner. Slide Mounts are
provided, but they are likely to only be for modern film sizes rather
than old glass-plate sizes. I just imagine pushing the plate into
the machine and having it slip or fall off.....Ugh!
I would normally suggest the first type - Scanner with a 'hood'.
There is only a small amount of preparation needed to make a flatbed
safe for scanning glass plates:
It is important that the glass plate is not allowed to touch anything
especially the glass platter of the scanner.
This can be done by using black card mount paper (conservation
quality) to make slide mounts that safely hold and locate the glass
plate a few millimetres above the platter of the scanner. It is
important that these mounts have plenty of gaps to allow air to
enter/escape without the two bits of glass being pulled together by
suction. I have heard of people removing the glass platter all
together and just supporting the glass slide over the scanning CD. I
am not sure about this on either conservation terms or for that
matter quality terms as it leaves the CD open to any stray dust/dirt.
It is also important to makes sure that when the hood is closed it is
held safely above the glass slide without coming into contact with it.
Due to the reasonable size of glass plates and indeed their
relatively low contrast range, they are not hard to scan and even
quite low end equipment can provide reasonable results.
Capture speed and throughput will largely depend upon the skill of
the operator and the bottleneck will be the safe handling of the
slides rather than the scanning itself.
Another possibility, mentioned above, is to use a digital camera. It
is quite possible to create a set up that allows much faster capture
of glass slides with even more conservational care. However this
will mean a larger investment in equipment. Your choice will be
either to buy a professional studio type camera and have quality 'at
a fair cost' or to use smaller SLR type cameras, which although
cheaper, can not compare with quality.
I hope this rather rambling answer will be of some help,
If TASI can be of any further help to you, please do not hesitate to
call us.
cheers
eib
--On 22 January 2004 09:59 +0000 Natalie Gibbs
<[log in to unmask]> wrote:
> Dear all
>
> The Dartmoor Archive is a recently established digitisation project
> which hopes, in its initial phases, to scan historic photographs of
> Dartmoor. We are supported by the Heritage Lottery and a number of
> Dartmoor organisations.
>
> We are at present looking into the possibility of purchasing a
> glass plate scanner, and would like some advice from those who have
> worked with glass plate scanners and know which ones do the job
> well.
>
> We have a number of different sized glass plates, so have decided
> to go for an A3 scanner, but would be interested to know good makes
> and models, so that we can make the best purchase!
>
> Can anyone help?
>
> Many thanks,
>
> Natalie Gibbs
>
> Project Officer
> Dartmoor Archive
>
> [log in to unmask]
>
> The University of Exeter
>
> _________________________________________________________________
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