Original Nikon 50mm f/2 from 1964 in Non-AI mount, classic Nikkor quality at the lowest possible pricing.
The Nikon Nikkor 50mm f/2 Non-Ai is a standard prime for the Nikon F mount from the pre-AI era (before 1977). Non-Ai = lacks the Automatic Indexing coupling tab for open-aperture metering. Optically equivalent to the Ai version. Nikon F mount.
f/2 maximum aperture. 50mm focal length (full-frame standard prime). Non-Ai coupling (pre-1977). Manual focus. At approximately 195g. Nikon F mount.
The Non-Ai 50mm f/2 is the earlier version without Nikon's 1977 Ai coupling update. Non-Ai lenses require stop-down metering on modern Nikon F bodies, or the AI conversion tab can be added by a technician. Optically the same formula as the later Ai version.
On the used market the Nikon Nikkor 50mm f/2 Non-Ai is an affordable vintage standard prime. Condition checks: front element, aperture blades, focus ring. Nikon F mount — Non-Ai (stop-down metering on modern bodies).