Craig,

My passion is Cypraea as well, and at the wise suggestion of a fellow
Conch-L'er I purchased a Visioneer flatbed with a single white bulb (my
other flatbed has RGB bulbs and did not do as good a job on 3D
subjects).   The bulb type appears to be key to a good 3D scan, if you ask
me.

My results with Cypraea have been more than satisfactory, although all of
my scans are for my database entries thus far (350 x 230 pixel
dorsal/ventral views and 300 x 150 pixel lateral views).  Higher resolution
scans have been good as well, but not what was needed at this point
anyway.   A recent scan of a C. hesitata came out particularly nice, in my
opinion.   All of my larger Cypraea scanned well, as a matter of fact.   I
have found a workable and acceptable depth of field of at least 50 mm and
up in many instances.   Keep in mind that I am not enlarging to printable
dimensions, but am scanning for an inexpensive means to add images to my
collection database.   In reverse, a tiny, beautiful 11 mm live collected
C. beckii scanned at 500 dpi was sharp and precise enough to document
features in all orientations; dorsally, ventrally and a lateral scan as well.

For dark shells, what I normally do is drape a plain white cloth over the
shell (I scan with the lid open or off).   I then can use layers in
Photoshop to adjust the background and subject if I want.  The white fabric
is essential for allowing a contrast to the dark shells.  Actually I use a
black velvet drape for lighter shells as well.  Velvet or a similar fabric
seems to give a smoother image in the end.

My suggestions, in contradiction with a few made previously, would be to
scan at a minimum of 150 dpi (I have repeatedly found 72 dpi scans just
totally unacceptable over and over) and decrease size of the object/image
in Photoshop thereafter.   The smaller the shell, the higher resolution I
will use; 300 dpi for most of my smaller specimens).   Never ever save to a
jpg format until the very last step; always save to .tif or a native
Photoshop format (.psd) while you're working.

I would be more than happy to share some of my Cypraea images if you like.

Best regards,
Nancy Smith