Panasonic LUMIX S 40mm F2

Reviewers find it sharp in the centre at f/2 and better than its price suggests. The extreme corners are weaker wide open, improve at f/2.8 and are at their best from about f/4 to f/11. Autofocus is quick, near silent and accurate, comparable to Panasonic's F1.8 primes. Distortion and colour fringing are low even without heavy reliance on in-camera correction, and flare and ghosting resistance is good, which matters because there is no hood. Vignetting is minor and fades by f/4.

Bokeh is the weak point. Backgrounds are pleasant but can look a little busy, and the seven-blade aperture gives polygonal highlights once stopped down. Testers praise the solid build for the weight, the metal mount, sealing and the extra function button. Most rate it a strong value as a small everyday prime and a lighter alternative to a 50mm.