Tokina has just announced a new wide-angle zoom lens for APS-C cameras, the AT-X 12-28mm f4. With a focal length equivalent to that of a 18-42mm lens on 35mm full-frame, the AT-X 12-28mm f4 offers a constant aperture rating of f4 at all zoom positions. Thanks to an optical design making use of aspherical elements and super-low dispersion glass, Tokina promises enough resolution to match even the highest megapixel-counting APS-C DSLRs currently on the market. A new AF mechanism furthermore promises faster and quieter autofocusing. Full specs after the break.