Minolta's rectilinear ultra-wide — the 17mm f/4 MC W Rokkor, a desirable early-70s wide prime.
The Minolta MC W Rokkor 17mm f/4 is an ultra-wide rectilinear manual-focus lens for Minolta reflex cameras from the MC generation of the early 1970s. The W prefix marks it as a wide-angle Rokkor and MC the meter-coupled series. At 17mm it was one of the widest rectilinear lenses in Minolta's range, keeping straight lines straight unlike a fisheye.
This is a manual-focus ultra-wide lens with a 17mm focal length and a maximum aperture of f/4, from the meter-coupled MC line. Only the focal length and aperture are affirmed; other construction figures for this specialist wide are not confirmed here and are omitted rather than guessed. As a rectilinear ultra-wide it uses a complex retrofocus formula.
The 17mm focal length gives an extremely broad rectilinear field for landscapes, interiors and architecture, capturing sweeping scenes while keeping straight lines straight. The f/4 maximum aperture is modest but adequate for the tripod and daylight work this focal length is usually put to, where depth of field is already generous.
On the used market this is an uncommon and desirable MC ultra-wide Rokkor sought by collectors and wide-angle enthusiasts. Because of its age, inspect for haze, fungus and separation across the wide front element, confirm the aperture is clean and responsive, and verify the focus ring is smooth. Check the coatings for wear, and use an adapter for mirrorless bodies.