The Sigma 800mm f/5.6 EX DG APO HSM is an apochromatic
extreme-telephoto lens with a fast f/5.6 maximum aperture. The
ultra-quiet Hyper Sonic Motor (H.S.M.) and Internal Focusing features
assist autofocus speed and handling.
The improved DG lens
design corrects for various aberrations. This lens is specially coated
to get the best color balance whilst cutting down on ghosting caused by
reflections from the digital image sensor.
This lens is ideal for capturing wildlife and sports photography.
Note! HSM lenses, while able to
manually focus with all Nikon F-mount cameras, will autofocus ONLY with
the following cameras- F6, F5, F4s, F100, N90s, N90, N80, N75, N70, N65,
D1 & D2-series, D50, D70, D100, Pronea 6i, and Pronea S (or newer
camera models). With other models, HSM or AF-S lenses must be focused
manually. This is the same limitation as Nikon's own AF-S lenses.