As its name suggests, the Tokina SZ 300mmPRO Reflex F7.1 MF CF is a reflex lens, aka mirror lens, although we’re not convinced about the ‘PRO’ monicker. Unlike regular camera lenses, reflex lenses adopt a catadioptric optical design, which basically means it does tricks with mirrors. Light enters the lens through a circular band at the front, is reflected back from a mirror at the rear to a second mirror positioned front center, which reflects it rearwards again to the image sensor. The light path is therefore effectively bounced back and forth twice as it passes through the lens, enabling a much shorter physical construction. Indeed, despite having an ‘effective’ focal length of 450mm on Fujifilm X and Sony E APS-C format cameras (480mm for Canon M), the lens is smaller than a regular can of drink and only about two thirds of the weight.
