I haven't done this before, but often it seems that people who post
answers have not read the previous posts, so here goes, a REpost
(with some minor additions):

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 lens protection 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, the hype in the advertising notwithstanding. The
(often more expensive) skylight filter adds a salmon-pink color shift
along with even greater (unnecessary) UV filtering, so its use should
probably be confined to specific instances when there is excessive blue in the image (if shooting slide film).
Hope This Helps