scanners for slides and digital camaras

[Roger J. Burkhalter]

On Sun, 2 Jun 2002 23:33:14 -0500, Heike Vibrans L <heike at COLPOS.COLPOS.MX>
wrote:

>Dear taxacomers,
>
>I am working on a grant proposal and would like your
>opinion on
>
>a) good-quality scanners for slides. I am thinking of
>scanning a collection of 12,000 slides, in the best
>quality possible. So I suppose it would be worthwhile to
>buy a scanner (vs. have the scans made). What are your
>experiences on price vs. quality, technical problems, and
>time investment per slide? I must add that it would
>probably have to be a product of a world-wide company, as
>it is often too complicated to buy products of small
>foreign companies without local representation here in
>Mexico.

We have found the time investment for scanning 35mm slides to be very high.
Most of the high quality film scanners are a three-pass type with
questionable color reproduction. The best quality scans we have made were on
a Nikon LS-4500 (no longer available, Nikon replaced with the 8000 ED). It
takes on average about 5 min. per scan at 3000 dpi including loading slide,
preview, cropping, focus and final scan, so your looking at aboutr 1,000
person hours.
>
>b) digital camaras with an optical (e.i. reflex-type)
>system. We have been working with a Nikon Coolpix 990 for
>two years, with quite satisfactory results, in general.
>However, there are two
>disadvantages: the autofocus doesn't like diffuse
>subjects, such as grass inflorescences, and it is very
>difficult to work with the manual focus under field
>conditions, because the small display is almost invisible
>in the sun. Also, the cards the camara uses only permit
>the storage of very few images in the high-quality mode.
>Finally, we would like to be able to use a proper macro
>lens.
>
We have switched from a Coolpix 950 to a Coolpix 5000 which has much better
manual controls. For macro work, we are using a custom adapter from Zarf
Enterprises to mount a Canon bellows to the camera (with a Nikon relay lens
between the camera and bellows) and a 80mm enlarger lens on the end of the
bellows. With this set-up, we can go from 1:1 to x15 with clear, manual focus
and great depth-of-field at f22. In macro mode we only work in b&w
(grayscale). We also save images at a minimal .jpg compression instead of
.tif files. We find no appriciable difference in grayscale images. This
outfit is a little bulky for some field use but is very sturdy with the Zarf
adapter (machined from solid brass). The same bellows could be used with a
Canon EOS D60 digital SLR camera with a canon EOS to FD mount adapter.

Roger J. Burkhalter
Curator/Archivist, Invertebrate Paleontology
Sam Noble Oklahoma Museum of Natural History
University of Oklahoma
Norman, OK