Youngnuo YN 40 mm f / 2.8 is the standard prime lens with a small footprint, designed to work with full-frame cameras with Nikon F mount Forty Yongnuo is for people looking for a clear, slightly wider than conventional 50 mm lens at an affordable price .
the optical design consists of six lens elements in four groups. The lens cooperates with the matrices full-frame, it will also work with cameras with APS-C. Sześciolistkowa aperture in combination with aperture of f / 2.8 provides a small depth of focus blur and pleasant. YN 40 mm has a built autofocus, the minimum focusing distance is 0.30 meters. On the housing YN 40 mm switch is MF / AF and manual focus ring.