What is the cheapest used Pentax 20mm f/4.5 in the UK?

The cheapest used Pentax 20mm f/4.5 currently listed is £29.99 at eBay, based on 7 listings compared across 3 UK retailers.

How many used Pentax 20mm f/4.5 are for sale in the UK?

There are currently 7 used Pentax 20mm f/4.5 listings available across 3 UK retailers on UsedLens, updated daily.

What sensor format does the Pentax 20mm f/4.5 use?

The Pentax 20mm f/4.5 features a other sensor.

Used Pentax 20mm f/4.5 for Sale — From £30

£29.99 Low price

£399.00 High price

7 Listings

3 Retailers

1 Reduced

Great for: landscape street travel

Compact ultra-wide manual focus prime for Pentax K-mount, sharp optics in a tiny package for landscapes and architecture.

The Pentax 20mm f/4.5 is a compact ultra-wide-angle lens from the mid-1970s, part of the original Pentax K-mount lineup that helped establish the bayonet mount standard. Its relatively modest f/4.5 maximum aperture was a deliberate design choice that allowed Pentax to produce an exceptionally small and lightweight wide-angle optic.

Optically, the lens delivers sharp results across the frame with well-controlled distortion for a lens of this focal length. The rectilinear design keeps straight lines straight, making it useful for architectural and landscape work. Some corner softness is visible at maximum aperture, but stopping down to f/8 brings edge-to-edge sharpness.

The compact metal construction is typical of Pentax lenses from this era, with a smooth focusing ring and firm aperture click stops. At just 20mm focal length, the depth of field is generous even at wider apertures, simplifying zone focusing for street and documentary work. The lens accepts 58mm screw-in filters.

On the used market, the Pentax 20mm f/4.5 is an affordable way to add ultra-wide coverage to a Pentax K-mount kit. Its small size and solid optics make it a practical choice for travel photographers who want maximum coverage with minimum weight in their bag.