The Nikon 55mm f/1.2 Ai is a fast standard prime lens for the Nikon F bayonet mount, built in the Ai (Aperture Indexing) generation that Nikon introduced in 1977. Designed for low-light shooting and shallow depth of field on 35mm SLR bodies, it sits in the classic manual-focus standard category alongside Nikon's slower 50mm primes.

Evidence in the UK auction market is thin: our records show a single hammer result of £110 in November 2025, and that figure is the only data point underpinning current value estimates. As of 2026 that sale price is what a tidy copy sells for at saleroom level (wholesale, before commission), but with so few comparables the realistic range a 55mm f/1.2 Ai is worth can move materially with condition, glass clarity and originality.