Olympus 50mm f/3.5 OM Zuiko Auto-Macro

The 50mm f/3.5 Macro Zuiko is a member of the first series of OM lenses, which were designed with an emphasis on small size and light weight without compromising performance, and it was the first macro lens for a 35mm camera that incorporated floating elements. The lens was designed for optimum performance at a magnification of ×0.1, and the floating elements minimise the aberrations that would normally be expected at higher and lower magnifications. The lens can focus from infinity to ½ life size. With the addition of a 25 mm Auto Extension Tube, the focusing range can be altered to cover ½ life size to life size (1:1). The extended focusing range compared with a standard 50mm lens requires a longer focusing helicoid, and in order to accommodate this the front element is recessed, providing a built-in lens hood. The non-macro Zuiko lenses have 2 focusing scales, one in feet with orange markings and the other in metres with white markings. The 50mm f/3.5 Macro Zuiko does not follow this pattern, and has a magnification scale with yellow markings plus one focusing scale in either feet (orange) or metres (white), and so there are separate versions with metric and Imperial focusing scales.