I want to get a couple different filters for my d40. I looked on ebay, and there are all sorts that fit my camera, and they seem cheap. some 23 piece kits with different colors and everthing. i think they would be fun to play with. I mainly want to use a just all around protection of the lens, and a poloarizing filter for reflective shots. can anyone point me in the right direction, and teach me about what filter to stay away from, or filters to buy? or just general info?