[Taxacom] Digital herbarium
fhaas at icipe.org
Mon Feb 22 03:33:13 CST 2010
Well, thats about correct!
I believe scanners came in since digital cameras did not offer enough
resolution some years ago when that all began. That has change
dramatically with sensors between 10-20 Mpix easily available. Forget
about the optical 'faults' of macro lenses, no way you see it on screen
or whatever, and I am sure the scanner has optical faults too (eg
looking obliquely on the margin areas). Optical quality is extremely
high these days (also because manufacturers had to adapt the lenses to
the resolution higher than film).
White balance: use fixed setting, and with all the different monitors
etc involved the colour will be different for all users, anyway.
Dust: well if you never change the lens that is no problem! So if you
have this camera for this set up only, its okay, and compared to here in
Africa, you museum is a clean room!
I would consider advantages in handling and speed of getting an image as
far superior to scanners (which also developed naturally).
Alan Franck wrote:
> We (USF) routinely use a DSLR camera for herbarium specimens. We use a high
> F-number to keep bulky specimens in focus, a high ISO, and two diffused
> flashes. Once setup (with the camera on a stand), the process is a breeze.
> Alan Franck, Ph.D. candidate
> Herbarium Assistant
> Dept. of Cell Biology, Microbiology, and Molecular Biology
> BSF 218
> University of South Florida
> Tampa, Florida 33620-5150
> On Sat, Feb 20, 2010 at 5:04 AM, Sean Edwards <sean.r.edwards at btinternet.com
>> Just a couple of points, mostly from a few years back when we considered
>> 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
>> 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
>> Dear members
>> 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
>> Associate Professor
>> SGTB Khalsa College
>> University of Delhi, Delhi
>> Taxacom Mailing List
>> Taxacom at mailman.nhm.ku.edu
>> The Taxacom archive going back to 1992 may be searched with either of these
>> (1) http://taxacom.markmail.org
>> Or (2) a Google search specified as: site:
>> mailman.nhm.ku.edu/pipermail/taxacom your search terms here
fhaas at icipe.org, Extension -2052
The African Insect Taxonomy Toolkit AITT
Dr. Fabian Haas
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