So I just got a D40x for graduation, along with some money and gift cards to a photography store in Canads (Black's). I was thinking of getting the 50mm. I know it's not AF-S, but how much of a bother would manually focusing it be? I'm looking at a budget of a little over $200 CDN, and the lens is about $180. It's a superb lens, so should I go for it? Also, I'd like a protective filter for my 18-55 so i don't have to use the lens cap. They have an Optex skylight filter... is this any good? It's cheap, but if there was a degredation in image quality, I don't want it.