Rokinon has announced the AF 24mm f/1.8 Compact, a wide-angle, fast prime that has a specific astrophotography mode to assist with star photography. This is Rokinon’s eleventh autofocus lens specifically engineered for Sony cameras.
The 24mm f/1.8 weighs a scant 8.1 ounces (~230 grams) and measures just 2.8 inches (~7.1 centimeters) in length. As the official name of the lens suggests, Rokinon promises that the lens combines a compact and light form factor combined with a wide-angle and fast maximum aperture that, along with a few custom features, the company says makes this 24mm lens “unmatched” by any other on the market.
The lens has three main features: a customizable focus-hold button (which is common on Sony first-party lenses), a custom switch, and the aforementioned astrophotography mode. The focus hold button keeps the lens locked at the autofocused distance and the button can also be assigned to other functions through the Custom Key Settings menu of the camera. Rokinon says the custom switch enables the focusing ring to function either as a manual focus control in Mode 1 or as an aperture control switch in Mode 2. The company plans to release additional functions via future firmware updates.
The astrophotography mode automatically sets the lens focusing mode to manual focus and then moves and locks the lens to infinity focus. It will confirm the lens is set when what Rokinon calls the Infinity Focus Confirmation LED shines green. If the focus control ring is moved, the LED changes to red.
Rokinon’s 24mm f/1.8 is made up of 11 elements in 8 groups, a promises edge-to-edge, corner-to-corner sharpness even wide open thanks to the inclusion of two aspherical elements, three high refractive index elements, and two extra-low dispersion elements. The company says that the spherical aberration and coma are highly controlled which are specifically important for astrophotography. Rokinon also weather-sealed five areas of the lens to protect it from dust, light rain, and snow (but do not grant the lens any specific IP rating).
The focusing system is a stepping motor design (STM) which the company promises to perform superb autofocus accuracy extremely quickly, precisely, and silently in both stills and video. The focus system is also internal, which means the lens does not change length at any time and allows for the use of 58mm polarizers and other filters.
Rokinon will retail the AF 24mm f/1.8 Full Frame Compact lens for $549 and expects to ship the lens starting in June.