I am brand new to the DSLR world, with 1 lens and no filters as of yet. The lens I have (the one thats in the Nikon D40 kit) accepts 52mm attachments. I was wondering though, is it worth it for me to get a larger filter with a step up ring and spend a little bit more money now instead of having to buy a whole new filter if the next lens I get is larger? I am looking at either a Nikon or B+W mc circular polarizer. (Also any suggestions on brand or additional filters would be appreciated!)