if you can, you should keep away from those push-pull type zoom lenses.. as was mentioned before they move during the exposure. great if you have a replica captain's chair and like staring at the picture going "maximum warp... engage!"
i feel that the 650-1300 lens would be next to useless because all those lenses i have seen or delt with have been absolute crap.
out of the 3 i would reccomend the 500mm f8 mirror lens.
Sigma has a 600mm f8 for about $650
|