The nikon fit tamron 90mm f28 macro lens has a built in motor and offers a medium telephoto focal length which makes it ideal as a portrait macro lens when used with a film camera when used on a digital slr camera with an aps c sized image sensor the lens provides a focal length equivalent to that of 140mm on a 35mm slr camera this means it can be used as a telephoto macro lens for digital photography the minimum focusing distance of this lens is 029m 114 in