Nikon 1's fast prime — the 18.5mm f/1.8 for sharp 50mm-equivalent portraits on 1-system.
The Nikon 1 Nikkor 18.5mm f/1.8 is a fast prime lens designed for the Nikon 1 CX-format mirrorless system, providing a 50mm full-frame equivalent field of view thanks to the system's 2.7x crop factor. It is widely regarded as the sharpest and most capable lens in the Nikon 1 lineup.
The lens delivers 18.5mm at f/1.8 maximum aperture, uses contrast-detect autofocus native to the Nikon 1 system, covers only the CX sensor format, and communicates full lens data electronically. Its compact size matches the Nikon 1 body's dimensions well for a truly pocketable combination.
The f/1.8 aperture gives the Nikon 1 system's small CX sensor its best available low-light performance, partially compensating for the sensor-size disadvantage versus larger systems. The 50mm equivalent field of view makes it the natural 'standard' prime for Nikon 1 photographers. The Nikon 1 system has been discontinued, making this lens available only on the used market.
Test autofocus speed and accuracy on a compatible Nikon 1 body — the contrast-detect AF system is the sole option. Check aperture blade condition and verify the lens mounts securely without wobble. Inspect the front element for coating damage. Note that as a discontinued system, repair support is limited and parts availability is low.