david_hansen11

I just played with my 18-200mm set around 50mm and a a good old fixed 50mm f/1.8 that I got on eBay for ~$50. I have a hard time seeing the differences in the center of the pictures, but the 50mm is *obviously* sharper towards the edges in my quick handheld test.

I don't know what people expect. The 18-200mm lens works over a huge zoom range and is small and compact. It's not the sharpest lens in the history of the world, but you have to compromise somewhere.

Think about it this way.

18-200: 16 elements in 12 groups

50mm:6 elements in 5 groups

The light in the 18-200mm lens is passing through almost 3 times as many elements and they are doing a lot more stuff than the 50mm elements are. That's just one tiny reason it isn't as sharp.

Or, you could do something crazy, and get a used or refurbished D50:

http://www.adorama.com/US%20%20%20%20294319.html

You can use all the old, cheap, crufty, fun lenses with it. It has a comparable sensor to the D40, although it doesn't do ISO3200, which I think the D40 can. Not that big of a deal in practice, though.

If you're worried about hurting the lens, you may just want to stick with UV filters. They'll work on a much wider variety of lenses than hoods will.

As far as "the flare thing" goes, I wouldn't go hunting out hoods unless you actually find yourself needing one. The coatings on modern lenses are quite good and we don't see flare like we did on older lenses.