The tokina 12 28mm f4 at x pro dx video lens has a super wide to standard zoom range while maintaining a constant fast f40 aperture designed specifically for users looking to shoot video with a dslr the lens comes equipped with a manual focusing ring and an interlocking follow focus gear to allow use with a cinema follow focus system although mainly designed for video the lens can also be used for taking stills in both mf and af by simply sliding the focusing ring forward and back on the le