Autofocus macro lens. The lens is also a fine short tele/portrait lens, with a field of view equivalent to 96mm* when used on a PENTAX 645D or 77mm* when used on a film 645 camera (*in the 24x36 format). This Macro lens features SMC (super multi coating) that significantly increase the amount of light transmitted by the lens. It also focuses as close as 39cm to achieve 1:1 magnification ratio