The yellow filter in the emulsion will block UV light from the red and green
sensitive layers. I don't know about the possibility of additional UV
blocking filters over the blue sensitive emulsion, but it could make sense.
You wouldn't use conventional color film for true UV photography anyway.
They make special (and expensive) lenses and thin emulsion films for the
very spcialized area of UV imaging, although you could probably get down to
around 350 nanometers with conventional equipment. Focus shift may be
important.

What many people call UV photography is color photography of fluorescent
objects. If that is what you want to do, you want to block the UV light
that excites the fluorescence. Otherwise, the UV light will overwhelm the
film and give you simply an overexposed, blue image. Generally you need to
use an additional UV blocking filter to capture the fluorescent colors. A 2E
is about the minimum. If you do not have important flourescence in the blue
region, use a No.8 yellow filter.

"HypoBob" wrote in message
...
A couple of years ago I read an article about UV photography and learned
that one problem that UV photographers have is that most color films
have a UV blocking layer that keeps UV away from the emulsion.

Does anyone know if any black and white films, particularly the newer
T-grain versions, have built-in UV blockage?

Thanks,
Bob