Hey all! Thanks for those that threw in their 2 cents about buying gear on Ebay. The reason for asking is that I want to buy a polarizer for my Nikon D70s. I've got the kit lens (18-70mm) and a Nikon 50mm (1.8f). Now the physical size of the two lens are very different (50mm is smaller). What is a guy to do? Buy two sizes? What are step-up/down adapters? How do they work. Is there a brand I should be going for? Are the cheap ones alright? Needless to say, I've got lots of questions. I want to amass the right equipment first rather than go through a bunch of junk. Thanks everyone!