Sony FE 100-400mm F5.6-8 OSS

Reviews call it competent rather than remarkable. Centre sharpness is good wide open at both ends and fairly even across the frame, but resolving power at 400mm is limited, so heavy crops and high-resolution bodies expose it. Stopping down gains little and costs light. Stabilisation is strong, around six stops in one test.

AF locks well in good light but can hesitate in overcast or dim conditions, partly because of the f/8 aperture. Bokeh is soft without onion rings, though highlights turn cat-eyed toward the edges. Results with teleconverters were described as poor, and reviewers recommend cropping instead.

Buyers like the price, the weight and the 400mm reach in a lens that fits a small bag, and the 0.41x close focus is popular for insects and flowers. Many describe it as a good first wildlife lens for 24-33MP bodies.

The main complaints are the f/8 long end in poor light, all-plastic construction, and AF that is less confident than G and GM lenses on erratic subjects. Owners stepping up from it usually look at the 200-600 G.