So I've finally accumulated a nice little collection of lenses. I was wondering what you guys do regarding choosing a filter size. Anyone here just buy separate filters for each lens? If not, how do you choose which filter size to go with? I my filter sizes are 37mm, 46mm, 49mm, 55mm, 58mm. And even then I'm not sure which of these lenses I will be keeping around. Should I just get step up rings to 58mm? Chances are I wont be keeping that lens (the 40-150mm). I've had it for 2 months now and haven't shot a single picture with it. Or any other size relatively more common/cheaper?