Carole, Paul et al

Thanks for the advice. Fossil shells don't generally fluoresce strongly, in
fact most are pretty weak, but nevertheless many do glow.

One problem I can think of with UV is that glass fluoresces and loses some
transparency. If the camera lens itself is hit by any stray UV it will
fluoresce diml violet, which may be enough to reduce crispness of the
image. it would be important to ensure the lens is shaded from direct UV.

I did get our Dept photographer to try B&W photography. He got some results
with about 3-minute exposures, but lost interest. I don't know what film he
used, but suspect his favorite, Ilford FP4. i guess if 400ASA film needs 1
minute exposure for a brightly-fluorescing Recent shell, the same film
would need at least 2-3 minutes for a dim fossil. I'll give it a go with
color film.

Regards
Andrew