Panasonic LUMIX S 18mm F1.8

Reviewers find the centre very sharp from f/1.8 and the edges good, improving when stopped down. Lateral and longitudinal colour fringing are well controlled, astigmatism is low, and focus breathing is negligible. Autofocus is fast, accurate and practically silent, which suits video. Lab measurements put its resolution a little behind Sony's 16mm and 20mm f/1.8 G lenses, but well within what the size and price would suggest.

The weak points are coma wide open, which matters for astrophotography, and noticeable vignetting wide open. Raw files carry heavy barrel and moustache distortion that the camera corrects. Opinions on rendering and flare differ: one test found onion-ring bokeh and weak resistance to bright light, while another saw well-suppressed flare and smooth backgrounds.