There’s a diverse range of manual-focus lenses from South Korean manufacturer Samyang, also badged as Rokinon lenses in the USA. The vast majority of them have no built-in electronics whatsoever, so you can’t control the aperture from the camera body, nor shoot effectively in Program, Shutter Priority, or scene modes.Instead, you need to dial in your required aperture via the lens’s own aperture ring, and the viewfinder image gets progressively darker with narrower aperture settings. Something of a rarity, this lens does have built-in electronics in the Canon-mount ‘AE’ version, enabling both camera-driven aperture control and operation of the focus confirmation lamp.
The focus ring has a long rotational travel and operates with smooth precision. Zone focusing is enabled by the focus distance scale and depth of field markings for apertures of f/2.8, f/5.6, f/11, f/16 and f/22.