Re: Experiences with digitizing material not suitable for aflatbed

From: David Adams (David.Adams@NATLIB.GOVT.NZ)
Date: Thu Apr 06 2000 - 19:07:43 CDT

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    Message-Id: <200004070012.RAA12676@dns.ccit.arizona.edu>
Date:         Fri, 7 Apr 2000 12:07:43 +1200
From: David Adams <mailto:David.Adams@NATLIB.GOVT.NZ>
Subject:      Re: Experiences with digitizing material not suitable for aflatbed
To: mailto:IMAGELIB@LISTSERV.ARIZONA.EDU

    <pre> Here at the National Library of New Zealand, Image Services - we write two CD copies of our 'master' digital files (hi-r s) We have over 250 CDs for our 15,000 image collection. One copy is used as our day to day working set and the other is stored in ideal conditions; low light, temperature and relative humidity, this set is not accessed. It is intended to be used as the 'digital file set' to migrate to the next stable platform as required in the future.

    David Adams Team Leader Copying Services National Library of New Zealand
    +64 4 4743151 Visit "Timeframes" New Zealands leading source of heritage images http://timeframes.natlib.govt.nz/

    >>> "LeMar,Greg" <mailto:lemarg@OCLC.ORG> 04/07/00 02:00 >>>
    Apologies for previous fragment posting. I am curious if anyone was concerned about producing an archival intermediate during the process of producing the digital file? Or, are there plans to make the digital file the archival copy?

    Regards, Greg LeMar Preservation Resources Bethlehem, PA

    -----Original Message----- From: Andrew Stawowczyk Long [mailto:mailto:anlong@NLA.GOV.AU] Sent: Thursday, April 06, 2000 12:39 AM To: mailto:IMAGELIB@LISTSERV.ARIZONA.EDU Subject: Re: Experiences with digitizing material not suitable for aflatbed

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    Mark,

    Here in the National Library of Australia we did couple of projects that involved digitising at high resolution. We aimed at 300dpi at 100%. As we were working with unique, fragile and oversized material
    (rare maps, manuscripts) we couldn't use a flat bed scanner. Instead we worked with high-end digital scanning back combined with a Sinar large format camera. It worked extremely well for most items achieving the required resolution. The back was Phase One with 8,400 x 6,000 pixel resolution and 36-bit internal colour depth. Some of the maps we needed to shoot in tiles, later stitching them together on a computer to get 300dpi resolution. It can be avoided by using a new Phase One back called Power FX with resolution exceeding 12,000 x 10,000 pixels.

    Some of the important things to be aware of:

    - Required light levels are very high - can be dangerous from the archival point of view.
    - Power conditioners (stabilisers) have to be used for lights as light levels have to be maintained very acurately during 5-20 minutes of exposure.
    - High resolution lenses (designed for digital capture) have to be used.
    - Powerful computers with large hard disks and a lot of RAM (500Mb - 1Gb) are needed.
    - Scanning back and computers need to be colour calibrated to a known standard (we use CIE D65) and colour profiles need to be used (ICC) to maintain colour accuracy throughout the system chain.
    - It is a common practice to capture at 36 or 48-bit colour depth and then reduce it to 24-bit for storage. It gives best results.

    Also, we evaluated an option for capturing images on film (4" x 5" transparencies) and scanning them later on but the results were not satisfactory. It was due partially to the much lower dynamic range of a photographic film than those of digital devices (typically for film it is 6 f-stops and at least 11 f-stops for high quality digital devices). Also, it is much more labor intensive and more expensive.

    I hope that'll help. Let me know if you need more info.

    Regards

    Andrew Stawowczyk Long Public Affairs Officer National Library of Australia Phone: +61 2 6262 1382 EMAIL: mailto:anlong@nla.gov.au

    >
    > >>> Mark Jordan <mailto:mjordan@SFU.CA> 04/06/00 11:02 >>>
    > Hi,
    >
    > We've been doing some research on the costs of equipment suitable for
    > digitizing material such as books, oversized posters, drawings, etc. that
    > we wouldn't want to (say pages from a rare and fragile book) or couldn't
    > (because of size) scan with a flatbed, even one with a 12x17" platten. To
    > get 24-bit color at a 300 dpi or higher, we'd have to spend quite a bit of
    > money.
    >
    > Does anyone have any experience with alternative methods of digitizing
    > largish-size material not suitable for scanning with flatbeds into 24-bit
    > color, high resolution images? For example, could photograph the items,
    > create high-quality prints or slides, and then scan the photo? Or is this
    > kind of method just not practical?
    >
    > Thanks for sharing any experiences you may have had with this kind of
    > material,
    >
    > Mark
    >
    > Mark Jordan
    > Librarian / Analyst, Systems Division
    > W.A.C. Bennett Library, Simon Fraser University
    > Burnaby, British Columbia, V5A 1S6, Canada
    > Email mailto:mjordan@sfu.ca / Phone (604) 291 5753 / Fax (604) 291 3023

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    <!doctype html public "-//w3c//dtd html 4.0 transitional//en">
    <html> Mark,
    <p>Here in the National Library of Australia we did couple of projects that involved digitising at high resolution.&nbsp; We aimed at 300dpi at 100%.&nbsp; As we were working with unique, fragile and oversized material
    (rare maps, manuscripts) we couldn't use a flat bed scanner.&nbsp; Instead we worked with high-end digital scanning back combined with a Sinar large format camera. It worked extremely well for most items achieving the required resolution. The back was Phase One with 8,400 x 6,000 pixel resolution and 36-bit internal colour depth.&nbsp; Some of the maps we needed to shoot in tiles, later stitching them together on a computer to get 300dpi resolution.&nbsp; It can be avoided by using a new Phase One back called Power FX with resolution exceeding 12,000 x 10,000 pixels.
    <p>Some of the important things to be aware of:
    <p>- Required light levels are very high - can be dangerous from the archival point of view.
    <br>- Power conditioners (stabilisers) have to be used for lights as light levels have to be maintained very acurately during 5-20 minutes of exposure.
    <br>- High resolution lenses (designed for digital capture) have to be used.
    <br>- Powerful computers with large hard disks and a lot of RAM (500Mb
    - 1Gb) are needed.
    <br>- Scanning back and computers need to be colour calibrated to a known standard (we use CIE D65) and colour profiles need to be used (ICC) to maintain colour accuracy throughout the system chain.
    <br>- It is a common practice to capture at 36 or 48-bit colour depth and then reduce it to 24-bit for storage.&nbsp; It gives best results.
    <p>Also, we evaluated an option for capturing images on film (4" x 5" transparencies) and scanning them later on but the results were not satisfactory.&nbsp; It was due partially to the much lower dynamic range of a photographic film than those of digital devices (typically for film it is 6 f-stops and at least 11 f-stops for high quality digital devices). Also, it is much more labor intensive and more expensive.
    <p>I hope that'll help.&nbsp; Let me know if you need more info.
    <p>Regards
    <p>Andrew Stawowczyk Long
    <br>Public Affairs Officer
    <br>National Library of Australia
    <br>Phone: +61 2 6262 1382
    <br>EMAIL: mailto:anlong@nla.gov.au
    <br><a href="http://timeframes.natlib.govt.nz/"></a>&nbsp;
    <blockquote TYPE=CITE>&nbsp;
    <br>>>> Mark Jordan &lt;mailto:mjordan@SFU.CA> 04/06/00 11:02 >>>
    <br>Hi,
    <p>We've been doing some research on the costs of equipment suitable for
    <br>digitizing material such as books, oversized posters, drawings, etc. that
    <br>we wouldn't want to (say pages from a rare and fragile book) or couldn't
    <br>(because of size) scan with a flatbed, even one with a 12x17" platten. To
    <br>get 24-bit color at a 300 dpi or higher, we'd have to spend quite a bit of
    <br>money.
    <p>Does anyone have any experience with alternative methods of digitizing
    <br>largish-size material not suitable for scanning with flatbeds into 24-bit
    <br>color, high resolution images? For example, could photograph the items,
    <br>create high-quality prints or slides, and then scan the photo? Or is this
    <br>kind of method just not practical?
    <p>Thanks for sharing any experiences you may have had with this kind of
    <br>material,
    <p>Mark
    <p>Mark Jordan
    <br>Librarian / Analyst, Systems Division
    <br>W.A.C. Bennett Library, Simon Fraser University
    <br>Burnaby, British Columbia, V5A 1S6, Canada
    <br>Email mailto:mjordan@sfu.ca / Phone (604) 291 5753 / Fax (604) 291 3023</blockquote>
    </html>

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    </pre>

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