I'm going to be maybe controversial here and suggest you don't use a filter!
After years of always having a filter on all of my lenses, I've done a complete 180 and haven't used any filters for the last ten years. My reasoning is this - I don't understand the logic of spending literally thousands of pounds/dollars/euros on cameras and lenses (giving you amazing image quality), then sticking a comparatively cheap piece of glass on the front of the lens!
My personal opinion is that the protection angle of a filter is way overplayed. I've been using SLR cameras since the mid-1970's (yes, I'm that
) and I have never scratched a lens or had a situation where a filter would have saved a lens. Over the years, as the quality of my equipment has improved, the idea of slapping a cheap bit of glass on the front of an expensive lens seems more and more absurd.
All just my own personal opinion on filters and I would point out that I do always use a lens hood.