The effects of UV filters

When shooting the photos of the range test for my PT-04 CN (or III's or GY's), I noticed that there were severe lens flares, most likely due to the cheap uv filter I had on my camera. I first noticed this the first time I took a picture of a Christmas tree, as there were several ghostlike flares all over the screen. These two picture below are with the filter (Rokunar 49mm on the Pentax 50mm 1.4 lens) that I found on one of the old lenses I purchased from a woman on Craigslist.


UV filters are basically plain pieces of glass designed to protect your camera from things that could contaminate the lens, such as a baby hand print. They supposedly help out with outdoor pictures as well, though I am uncertain exactly how. The better UV filters (and I do NOT have one of those) have special optical coatings like the coatings on your lens so they will not cause these flares.

So my $5 UV filter arrived today from Hong Kong along with a step up ring, and I tried it out under similar conditions without the flashes firing in the distance. Again, there are lens flares in the photo.


So I tried one last photo, this one without any filter at all. This photo shows no lens flare at all.


I wish there were a moral to this story, but I don't really have one. It probably isn't worth the $40 for a multi coated filter for an $80 kit lens, not would I recommend going without a protective cover unless you are in control of your conditions such as in a studio. You are just better off taking off your uv filter whenever this occurs. If I had a really nice lens, I would probably spend the $40 on a filter, but I don't have the expensive lenses to merit the cost.