The pentax 40mm f28 da limited lens black is an ultra slim and lightweight k mount prime lens offering an equivalent focal range of 61mm in 35mm film format the limitation of a fixed focal length 40mm allows you to see the world from one perspective encouraging you think outside the box and become more creative with your photography the pentax limited series lenses are renowned for their hand machined well built aluminium body outstanding image quality hd coating and a round shaped diap