I have a Nikon D50 with stock 18-55 lens. I've been doing a lot of work in low light situations lately and long exposures are not an option. I've no speedlight or other lenses. It's mostly indoor work shooting dance instructors and performers. While I would prefer Nikon lenses, budget is an issue since I'm a poor college student. :er: What lens(es) would you recommend for me? Should I aim for a lens with a larger aperture or one where (I'm not really sure what the term is, but I'll elaborate) the lens has a larger size (larger size filter). Should I invest in a speedlight or should I get a lens?