Most people use UV filters to protect the front element.
If using a filter system like lee, I tend to just leave the filter holder ring attached to the lens and use a lee filter holder cap.
http://www.amazon.co.uk/Lee-Filters...DZWC/ref=sr_1_1?ie=UTF8&qid=1343196440&sr=8-1
Hotshots said:As has already been posted, Yes your cap will fit over any screw in UV or Polariser.