UV filter causes halos and disco effects
 

Has anyone else had any weird results from their
Canon UV filter. It seems like everytime I use it in poorly lit situations I get some weird halos or stobe effects around headlights and other flashing lights. I was thinking that I might have my f-stop set to low. It has happened a few times when I had the camera set up to f1.6-2, 1/30th-160th on the shutter, no gain, autofocus off, preset outdoor white balance. I have cleaned the lens and filter but they really werent that dirty. I have some frame grabs but I dont have a site to post at.

This is common, particularly for dark scenes with bright points. Sometimes called "fireflies", it's caused by reflections bounced between the lens and the filter. Solution: take the filter off the lens.

Ryan,

Good quality COATED filters are less likely to cause this effect. May want to try a different filter.

I had the same problems with a cheap UV filter. Now I am using a Hoya filter - works perfect, without halos and other unwanted effects.

Thanks a bunch for the input. I thought maybe since it was a Canon Filter it would be adequete, I recall it wasnt much money. I will try out another brand sometime soon.