In article <4gh54e$ks@aldus.northnet.org>, sproulx@northnet.org says...

>Why is a UV filter used and what kind should I use. Can this be used
>indoors? I know they are good for protection but what else?

Not much, but that may be enough reason to use one. Good UV filters
have no detectable effect (good or bad) on the photo image (most
lenses stop most UV without using a filter, and my tests indicate no degradation of sharpness when using good-quality filters). I would include the relatively inexpensive Hoya filters in the "good" class
of filters, and I think there is little need to spend more than
the cost of these. Multicoating for filters is an unnecessary
additional expense, IM(NS)HO.
Hope This Helps