[Taxacom] Digital herbarium
sean.r.edwards at btinternet.com
Sat Feb 20 04:04:07 CST 2010
Just a couple of points, mostly from a few years back when we considered this:
1. Problem with scanners is that it means either turning specimens upsidedown (bad thing), or buying an expensive upsidedown scanner. We made a transparent folder for turning specimens upside down, but handling and electrostatic problems caused more damage.
2. Problem with DSLR cameras is the usual:
a. they need a copy stand to keep them square (no too much of a problem);
b. even the best macro lenses will have optical faults (most now are very good, and things like lateral chromatic aberration can be routinely sorted afterwards);
c. dust on sensor (standard DSLR problem even with self-cleaning sensors, just something you have to deal with);
d. white balance, even lighting, etc. (no real problem, just be aware of it in your set-up -- four flash guns evenly cornered at good distance and 45 deg, but just two at the ends works perfectly well).
Maybe scanners have moved on recently?
Sean Edwards, email: sean.r.edwards at btinternet.com
----- Original Message -----
From: Gurcharan Singh
To: taxacom at mailman.nhm.ku.edu
Sent: Saturday, February 20, 2010 6:35 AM
Subject: [Taxacom] Digital herbarium
For some time I was thinking of initiating a thread on digitising herbarium specimens, but was reluctant because whenever there is mention of digital herbarium, there is always mention of a scanner. I have worked with scanners (though not high end ones), but always find a good digital SLR camera giving very good results. I had started this with old photographs in our family albums, and when I thought of digitising my personal and College herbarium specimens, I found Digital SLR camera much more handy and useful. Today I got this encouragement from MBLWHOI Library Digital Herbarium.
"Specimens too bulky or fragile to be scanned will be photographed with a digital camera"
Personally I feel Digital SLR camera is much more useful, as it saves a lot of time as compared to a scanner. My question is if Digital SLR camera can give good results with fragile and bulky specimens, and is much more faster than a scanner, why not to use it in routine procedures.
May someone with good experience with both can give better opinion.
Dr. Gurcharan Singh
SGTB Khalsa College
University of Delhi, Delhi
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