Message-Id: <199905191245.FAA25822@dns.ccit.arizona.edu> Date: Wed, 19 May 1999 08:18:03 -0400 From: "Jerome B. Skapof,Ed.D" <mailto:skapof@SOVER.NET> Subject: Re: Digital Camera for poster project To: mailto:IMAGELIB@LISTSERV.ARIZONA.EDU
Dear James and Virginia; I'm sorry I left out some information regarding alternative light sources for scanning backs. James is course right about long exposure times on line scanning backs and the use of Flicker Free Florescence will help with keeping heat of the art. However, and I'm sure this subjective, many copy photographers feel they get better results with a harder light. That means tungsten or HOT lights which are not acceptable for obvious reasons.There is however, although not inexpensive, new lighting systems in use at MOMA, Harvard, University of Indiana, and several other institutions which use a "HEATLESS" tungsten bulb. These are high intensity dichroic coated quartz hallogen blubs housed in special reflective fixtures which also contain built in forced air cooling. The dichroic filter reflects IR that produces the heat in the opposite direction of the art. While ambient temperature will rise a little, the art work stay a room temperature. Thus, the best of both possible worlds.
Info on these "heatless" lights can be found on:
www.academicimaging.com.
Jerome Skapof, Ed.D VP, EIN 802-362-3169 mailto:skapof@sover.net
James Otto wrote: >
> There is one other lighting option to be considered. High-output flourescent lights
> on light stands provide lighting of equal or superior quality to tungsten (hot!)
> lights but they put out very, very little heat. That's why we use them with our
> digital camera (actually a medium-format film camera with a digital scanning back)
> to image delicate special collections materials, because we need a cool light source
> to provide lighting for scans that can take three minutes -- without damaging the
> materials scanned. The only drawbacks to this are that flourescent lighting can be
> expensive and you may need a filter for the camera lens to compensate for the color
> of light that can be emitted by flourescents. But we've been very happy with the
> results.
>
> For a look at a sample what we've done with our setup, see
> http://voxlibris.claremont.edu/sc/events/accent/lo_accentonimages.htm --all images
> were made with a PhaseOne Studiokit digital scanning back system lit by North Light
> flourescent lamps. For a look at PhaseOne and North Light products, see
> http://www.phaseone.com/ and http://www.northlightproducts.com/html/digital.htm
>
> --James Otto
>
> "Jerome B. Skapof,Ed.D" wrote:
>
> > Virginia: Beside the large pixel count and file size generated by
> > digital cameras to capture the print on posters, you also have to
> > consider the lighting requirements and productivity issues. All digital
> > cameras with the exception of just one, require hot lights to do large
> > captures (line scanners). Only the Jenoptik LOS eyelike can use strobes
> > for a res. of 6X6. Additionally, line scanning backs are have extremely
> > slow scan times. Scanning backs and cameras that use PAD (Piezo Aperture
> > Displacement or Micro Scanning) can to captures of 100 MB or more in 60
> > seconds.
> >
> > You might want to check out a site that lists and discusses all these
> > high end cameras and related technology...academicimaging.com for ideas
> > and a detailed explanation of PAD.
> >
> > Jerry Skapof, Ed.D
> > V.P., EIN, Inc
> > mailto:skapof@sover.net
> > 802-362-3169
> >
> > Virginia Kerr wrote:
> > >
> > > Are you hoping to use a pixel dimension large enough to read any small text
> > > on the posters in your high resolution scans? I'd be interested to see
> > > what specifications you're developing. For two poster digitization
> > > projects at Northwestern University we had the posters photographed and
> > > scanned from the film. Since that was a couple of years ago (1996-7),
> > > we've recently considered a new poster project using a digital camera.
> > > But we're put off by the pixel dimensions required to capture all text from
> > > something the size of an average poster.
> > >
> > > -- Virginia Kerr
> > >
> > > World War II Posters from Northwestern University Library
> > > http://www.library.nwu.edu/govpub/collections/wwii-posters/
> > > Posters from the Herskovits Library of African Studies
> > > http://www.library.nwu.edu/africana/collections/posters/
> > >
> > > At 04:38 PM 5/13/99 -0600, you wrote:
> > > > I am looking for the best, but reasonably priced, digital camera
> > > > (preferably $1,000 or less) to capture images of (for access purposes
> > > > only) the McCormick-International Harvester Co. posters we will be
> > > > physically preserving and storing.
> > > >
> > > > I would like to find a reasonably priced camera that will give us the
> > > > highest quality image currently available.
> > > >
> > > > Anyone compared digital cameras recently? Are there guidelines for
> > > > comparing digital cameras? What should I be looking for? Could
> > > > anyone help me cut to a manageable one or few cameras to compare and
> > > > select among?
> > > >
> > > > Thanks, in advance.
> > > >
> > > > Sharlane Grant
> > > > Preservation Officer
> > > > State Historical Society of Wisconsin
> > > > mailto:st.grant@ccmail.adp.wisc.edu
> > > > 608/264-6474
> > > >
> > > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> > > Virginia Kerr
> > > Preservation Digital Technology Librarian
> > > Northwestern University Library mailto:vkerr@nwu.edu
> > > 1935 Sheridan Road VOICE (847)491-7786
> > > Evanston IL 60208-2300 FAX (847)491-8306
> > > http://www.library.nwu.edu:80/preservation/
> > > %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> --
>
> James A. Otto
> Digital Projects Specialist and ERes Manager
> Honnold/Mudd Library Special Collections
> (The Libraries of The Claremont Colleges)
> 800 N. Dartmouth Avenue
> Claremont, CA 91711-3991
>
> (909) 607-7530 (x77530) (Phone)
> (909) 621-8681 (Fax)
> mailto:jotto@rocky.claremont.edu
>
> "The highest reward for a man's toil is not what he gets for it,
> but what he becomes by it."
> --John Ruskin