Nikon's AI-era fast fifty — the 50mm f/1.4 Nikkor-S in AI specification for full metering support.
The Nikon Nikkor 50mm f/1.4 AI is the AI-converted or AI-native version of Nikon's classic fast standard prime. The Nikkor-S designation indicates an earlier optical version updated with AI coupling for compatibility with newer Nikon bodies. At f/1.4, it was the fastest standard lens in Nikon's lineup, prized for shallow depth of field and low-light capability.
Optical performance is good with distinctive vintage character. Sharpness is soft at f/1.4 with a pleasant glow, improving significantly by f/2 and becoming excellent by f/4. Bokeh is smooth with seven aperture blades. The rendering at wider apertures has a dreamy quality that many portrait photographers find appealing. Colour rendition is neutral with Nikon's multi-coating.
Nikon F mount, AI specification with manual focus. Filter thread is 52mm. Weight is approximately 250 grams — compact for a fast fifty. Build quality is excellent with all-metal construction and a smooth, precise focus ring. The AI coupling provides full metering on compatible Nikon bodies. Several optical versions exist — earlier 7-element and later 7-element designs.
Common on the used market at moderate prices — more expensive than the f/1.8 but still affordable. Check for smooth focus ring and clean optics. An excellent manual focus fast fifty that remains popular for its rendering character. The extra stop over the f/1.8 is valuable for low light and shallow DOF work.