Nikon's compact AI-S fifty at f/2 — a sharp, affordable standard prime from the manual focus era.
The Nikon Nikkor 50mm f/2 AI-S was introduced in 1979 as part of Nikon's AI-S lens lineup. It occupies an interesting position — slower than the f/1.8 and f/1.4 alternatives but even more compact and lighter. The AI-S specification provides linear aperture response for improved automatic exposure accuracy on bodies that support it, particularly in shutter-priority mode.
Optical performance is very good. Sharpness is excellent from f/2 — better wide open than the f/1.8 or f/1.4 at their respective maximum apertures. The simpler optical design with fewer elements produces clean, contrasty images. Bokeh is pleasant with six aperture blades. The f/2 maximum aperture is more than adequate for most shooting situations.
Nikon F mount, AI-S specification with manual focus. Filter thread is 52mm. Weight is approximately 170 grams — very compact. Build quality is excellent with typical Nikon metal construction. The AI-S linear aperture coupling provides improved exposure control over the AI version. The lens is compatible with every Nikon F-mount body ever made.
Affordable on the used market though less common than the f/1.8 version. Check for smooth focus ring and clean optics. An excellent compact fifty for photographers who value portability and don't need the extra half-stop of the f/1.8. The sharper wide-open performance is actually an advantage over the faster alternatives.