I would use a UV filter if I felt it would be necessary for exposure control. Example, suppose I felt that I needed the extra precision offered by (also debated at length ... a Zone VI modified light meter). One of the interesting stories that Fred Picker told about the Zone VI modification is that, although he did include an IR blocking filter, he did not modify the meter on the UV end of the spectrum. For this, he said, you use a UV filter on the meter... and a UV filter on the camera. If I didn't want to make Fred turn over in his grave, by gum, I would use a UV filter if I used a Zone VI modified meter.