Re: Glass slide imaging

From: Andrew Stawowczyk Long (anlong@NLA.GOV.AU)
Date: Mon Aug 21 2000 - 18:47:52 CDT

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    Message-Id: <200008212349.QAA25314@dns.ccit.arizona.edu>
Date:         Tue, 22 Aug 2000 09:47:52 +1000
From: Andrew Stawowczyk Long <mailto:anlong@NLA.GOV.AU>
Subject:      Re: Glass slide imaging
To: mailto:IMAGELIB@LISTSERV.ARIZONA.EDU

    <pre> Emil,

    I have extensive experience with scanning glass negatives. We did a lot of this here at the National Library of Australia. In my opinion there are a few important factors to this. Firstly, you need to be able to put negs on the scanning plate in such way that the transparency lid is not touching them but is positioned above - that prevents any unnecessary scratches and abuses of the emulsion. Secondly, especially with old negs it is important that scanner has a dynamic range exceeding 3.5. With such range you will be able to obtain excellent results capturing deep shadows as well as highlights in a scan. Thirdly, if you want to capture maximum detail you need at least 1500dpi (I prefer 2000 minimum) resolution for older negs and something like 2500 - 5000dpi for other. Of course, it is often impractical so we decided on scanning at 2000dpi. Those are the most important things to consider. However, there are other things as well. For example, Lowan Turton mentioned in another email MOIRE pattern when glass surfaces touch each other. In this case it is not MOIRE, it is phenomenon called "Newton rings" and can be avoided by using special, anti-Newton glass. Most of times Newton rings are not a problem as usually the emulsion side touches glass. As for the scanners, we use ScanView F6 but it is very high-tech and very expensive device. For cheaper options I would recommend AGFA T2000.

    Regards Andrew Stawowczyk Long Manager, Photographic Services National Library of Australia
    +61 2 62621382 mailto:anlong@nla.gov.au

    Emil Levine wrote:

    > > ----------
    > > From: Emil Levine[SMTP:mailto:ELEVINE@UNIDO.ORG]
    > > Sent: Monday, August 21, 2000 11:22:24 PM
    > > To: mailto:IMAGELIB@LISTSERV.ARIZONA.EDU
    > > Subject: Glass slide imaging
    > > Auto forwarded by a Rule
    > >
    > Dear Colleagues,
    >
    > I have an urgent requirement for information about scanning
    > photographs from glass plates. I will need up to 600 DPI. Help.
    > Any recommendations for equipment, DPI.
    >
    > Thanks in advance.
    >
    > Emil Levine

    </pre>

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