Panasonic LUMIX S PRO 70-200mm F4 O.I.S.

Reviewers report excellent sharpness and contrast across the whole zoom range, even wide open at f/4, with only a small drop-off at the extreme edges and corners. Colour fringing is minimal, distortion is effectively zero with in-camera correction, and ghosting and flare are well controlled. Autofocus is quick, quiet and accurate, and the stabiliser is highly effective. Background blur is pleasant for an f/4 lens, aided by the rounded 9-blade aperture.

The build is solid and weather resistant, and the included tripod foot is welcomed, since rival f/4 zooms sell it separately. The main criticism is price: both reviews call it expensive next to 70-200mm f/4 zooms from other brands. One also notes that the push-pull focus ring will not suit everyone. Both recommend it, and one argues it is the more sensible choice than Panasonic's f/2.8 unless the extra stop is essential.