Re: Experiences with digitizing material not suitable for a

From: Patricia Bruce (PBruce@swri.edu)
Date: Thu Apr 06 2000 - 09:31:21 CDT

  • Next message: Eileen Mathias: "Scanning largish items" 

    Message-Id: <200004061433.HAA16522@dns.ccit.arizona.edu>
Date:         Thu, 6 Apr 2000 09:31:21 CDT
From: Patricia Bruce <mailto:PBruce@swri.edu>
Subject:      Re: Experiences with digitizing material not suitable for a
To: mailto:IMAGELIB@LISTSERV.ARIZONA.EDU

    <pre> We believe that handing originals should be kept to a minimum...therefore we produce an archivally processed photographic color and black and white film copy as well as an archive of our digital files on CD and tape...maintaining the digital file information and documenting the program process for future upgrade..... Patricia Bruce, archivist/librarian SwRI

    "LeMar,Greg" <mailto:lemarg@OCLC.ORG> Wrote:
    |
    | 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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    | Content-Transfer-Encoding: 7bit
    |
    | 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
    |
    | --------------201CB6430B73D0AB615741D5
    | Content-Type: text/html; charset=us-ascii
    | Content-Transfer-Encoding: 7bit
    |
    | <!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>
    |
    | --------------201CB6430B73D0AB615741D5--
    |

    </pre>

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