Well....I am not very impressed with my 60 - 300, It's difficult to focus and it's construction is poler opposite of my 80 - 200 (a lens I have gotten used to). A major reson I bought it was for shooting some youth sporting events. Now the soccer games I am not too worried about, however the lacross games have me a little conserned. These are kids who are really just learning and enjoying the game so I antisipate strey balls going off in random directions. With lacross the ball is smaller and heavy thrown with equipment, I can't garentee wether I will be able to move in time (bare in mind, these are youth events....there are no grandstands just a playing field). Now since I do not want a lacross ball for a front element I figure I'd throw a a couple filters on to the lens just in case (a lacross ball thrown by even a child will destroy one in a hurry), My disposable filter collection is restricted to 62mm, and I have only two 62mm lenses, the 60 - 300mm Canon mount zoom and a 200mm Pentax mount tele. I full well intend to use the Canon for this so the 200mm is out. If I can get away with stacking on this lens I might use it, but it's it's only saving grace at the moment. If the effects are estimated to be too deliterious to the shot, I'll just shoot with 400mm form further away and holler at people who get in the way. So my question is, What should I expect at the best and the worst of two or more filters on my FD zoom lens?