The Next generation of AT-X is the AT-X PRO SV series. The fist introduction is the AT-X 287 AF PRO SV, an exceptional 28-70 f/2.8 auto focus lens. With its emphasis on value, its cornerstone is its heritage of Tokina HLD optical glass. Advancements in fabrication technology and the greater use of composite materials have created a lens that is lighter in weight yet more substantial value. The constant f/2.8 aperture makes focusing and shooting in low light situations much easier than other standard lens with smaller apertures. An internal focusing system couple to a Focus Clutch Mechanism yields quick and quiet auto focus as well as smoothly damped manual focus action.