I have a tripod, so I'm good there. Now I have a dilemma as to what telephoto lens to get for wildlife shots. I need to keep the cost down. I was looking at a Canon EF-S 55-250mm f/4.0-5.6 IS, but have been told that it wouldn't allow enough light. So now I need suggestions on a lens that would be good for wildlife, but won't cost me a fortune. I need to keep both camera and lens in the $1000 range. I know that's tough. Any ideas would be great.
For shooting in daylight an f/4-5.6 will be fine. It's only inside or at night you need a fast lens f/1.8 or f/2.8.
For wildlife, you'll need to get close to the animal with a 250mm lens.
Serious wildlife photographers gavitate towards 600mm prime lenses and gimbeled tripod mounts (expensive gear) .
Two other points, and what follows is opinion.
When you choose a camera brand you are also commiting to that brands lens lineup and general philisophical approach to camera and lens design.
Right now, Nikon is making cameras that out perform what Canon has to offer when it comes to image quality. In general, equivalent Nikon cameras have better RAW image quality because they have more color depth, dynamic range and ISO performance. Nikon is accomplishing this with fewer mega pixels and most of their cameras also have color aware metering as well. Canon recently introduced their first camera (7D) that has color aware metering. You can check my claims about image quality by visiting the web site of an independent testing lab
www.dxomark.com
As far as used, the used entry-level Canon cameras generally out perform Nikon's earlier entry level cameras (D40, D60, D70, D80), and that's why I mentioned the commitment to a design philosophy, lens lineup, and the possibility you may want to upgrade for better image quality down the road.