how important is UV filter for dust protection

[jeffkohn]

As others have mentioned UV filters can cause glare/ghosting or loss of contrast in certain situations. I think the "protection factor" is debatable. In most cases a hood will provide enough protection just by preventing incidental contact with the front element that could result in scratches. Sure there are extreme cases such as the one mentioned above where a hood is insufficient but I don't think a filter would provide much protection for that kind of contact. In fact I've heard of cases where the UV filter shattered on impact and caused extensive damage to the front lens element.

The one place I could see a UV filter providing beneficial protection is around the beach/ocean or other places where there could be airborne contaminants you want to keep off the glass.

I don't use UV filters anymore, it just didn't seem worth it for the questionable benefit. If one of my lenses sustains accidental damage, the insurance company will pay for the repair.

I do often use polarizers and/or hot mirror filters though.

[Scott-Tx]

if you buy good, coated filters (read B+W or Heliopan) and keep them clean, you should not have any issues with ghosting that you wouldn't have w/o the filter in place. the first thing i do when buying a lens is clean it very carefully and fit it with a b+w kr1.5 filter. even at $80 or more, it's a small price to pay to keep my glass it top condition. every 18 months or so, the filters need to be replaced... if it weren't for them, all those little cleaning marks and scratches would be on the front element of my lenses and not on a filter that can be easily replaces.

if you only shoot occasionally or in a studio, they are unnecessary, but if you shoot regularily, and outdoors, i would recommend them without question.

i've done tests under a 50x loupe and have never noticed the slightest bit of degradation caused by good filters. so, aside from the relatively small cost, why not use one?