Sigma 150-500mm f/5-6.3 DG OS HSM £700, $1070
The cheapest lens in our group loses out to a couple of newer designs, but is still great value
Anybody looking for serious telephoto reach at a bargain price should find this Sigma a good compromise. It has a variable (and not terribly fast) widest aperture of f/5.66.3, but the trade-off is that it’s quite light, at just 1.78kg. The build is basic, without weather seals or even a rubber sealing ring on the mount, and there’s no focus-range limiter switch, but plus points include ring-type ultrasonic autofocus and a dualmode optical stabiliser offering both static and panning modes.
Optical construction includes three SLD (Special Low Dispersion) elements which are designed to help with chromatic aberration (colour fringing), and Sigma’s ‘Super Multi-Layer Coating’ to reduce ghosting and flare. The filter thread is typically large at 86mm, but still smaller than in the newer Sigma and Tamron 150-600mm lenses.
Image quality is respectable for a super-telephoto zoom lens at this price. Sharpness is good throughout the zoom range, but it’s best to stop down to around f/8 at the long end of the focal length range, where lateral chromatic aberrations are also more noticeable than with competing lenses in the group. In our lab tests, the stabiliser gave an improvement equal to about three stops.