Carl Becker , Dec 15, 2008; 04:02 p.m.
I have purchased and used a Nikkor 300mm f4 with TC, a Nikkor 400mm f5.6 ED-IF and currently a Nikkor 500mm f4 P with TC on either a D200 or currently a D700. I try to capture images of small birds while walking in the woods. I have had some success. The longer and faster the lens the better. If you have a feeder and can get close then the 300mm is great. For best value I would look for a 400mm Nikkor manual focus or thrid party with AF. I am finally happy with my efforts using the 500mm f4 P. It is very much worth the saving for the cost of a used lens. Sigma made a 500mm f4.5 AF.