digital images of type specimens
bneill at LCLARK.EDU
Tue Aug 22 10:48:33 CDT 1995
At 10:53 8/22/95, Shawn Landry (BIO) wrote:
>Please let me know if this is a repeat of a previous thread...
>I am looking into the various techniques to take digital images of type
>specimens and would like to speak with anyone else involved with the
>issue. I am in need of specific product info as well as information
>regarding the best (or most appropriate) techniques. Specifically, I
>would like to hear from people who have compared the use of a digital
>camera with that of a video camera and video capture technique and/or
>scanning of 35mm slides.
>The main conflict (as usual) is between resolution and affordability and
>usefulness of the images to the scientific community.
>Shawn Landry Landry at chuma.cas.usf.edu
>Dept. of Biology LIF 136 (813) 899-0989
>University of South Florida
>Tampa, FL 33620-5150
I have been using video captures to create images from specimens under
dissecting microscopes. It has worked quite well, but the resolution is
not as good as it might be from scanning 35mm slides. It is also not as
good as digital. I compared images from digital and video capture and
found the digital to have abit more contrast. The difference was not worth
the hassle of the digital camera over video (the capturing process was much
faster on video and I was capturing a large number of specimens for
analysis). If I understand the technology correctly, the digital will
always yield better resolution than a video capture given hardware of
roughly equal capacity. The inherent problem of video is in freezing a
single frame - much like the pause on a VCR. I cannot comment on the
relative abilities of digital vs. 35mm. I think that Doug Yanega is
absolutley correct about the weak link being the printing process (for a
reasonable amount of money).
We have been using NIH Image to capture video images. The software works
very well and greatly facilitates making quantitative measurements on small
specimens. Image is a public domain program for Macs. I do not know
whether it is available for PCs.
I would love to hear any infromation you might gather during this
investigation of image capturing techniques, as I would like to get more
resolution than I am getting now with minimal expenditures.
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