Can I retract what I said about Marumi filters? Perhaps I just need one of the more expensive Marumis....
Put it on my 70-200 (on my now arrived 40D

) and had a play. Forgot it was on there and started shooting at 200mm/f4. Bloody thing wouldn\'t focus!
I\'m thinking it\'s my nice new 40D body as the lens worked fine the other day. I stick the lens on my 400D and lo and behold, same results. BASTARD! I\'m thinking that the lens is going to have to go back - all my other lenses are working just fine.
Sat fuming for two hours, then suddenly realise I\'d stuck the CPL on the end yesterday and hadn\'t tested that. Off it comes and back come the razor sharp focus/images.
Guess I\'m going to have to splash on filters that do the optics justice. Saying that, I\'ve just whacked a cheap UV on it and that works fine.
At least the Marumi doesn\'t screw my 17-50 up too much. I\'ll use it on that. Hoya or more expensive it is for L lenses then
