PENTAX HD 31mm f/1.8 Limited Silver camera lens

A 31 mm f/1.8 prime for Pentax K-mount

This silver-finished Limited lens delivers a 31 mm focal length that becomes 47.5 mm on APS-C bodies, giving a natural perspective for street, landscape and portrait work. Its fast f/1.8 maximum aperture and nine-blade rounded diaphragm produce smooth background separation. The HD coating cuts flare and ghosting, while the fixed hood adds front-element protection. Build quality is precision-machined aluminium throughout.

Behaviour under sustained shooting

The HD coating maintains contrast and colour fidelity when the lens is used wide open in strong backlight, preventing the veiling flare that builds up during long sessions. The rounded diaphragm keeps bokeh discs circular even after many aperture cycles, so highlight rendering stays consistent. No focus-shift or thermal drift is mentioned in the specifications, so critical sharpness should remain stable across extended use.

Installation and common pitfalls

The lens mounts directly on any Pentax K-mount body without an adapter; the aperture ring allows both automatic and manual exposure control. Because the hood is fixed, screw-in filters must be threaded behind it, which can be awkward with thick polarizers. The focus ring rotates during autofocus, so keep fingers clear. No weather-sealing rating is provided, so avoid heavy rain or dust.