Sigma 120-300mm f/2.8 DG OS HSM S £2700, $3600
What this beefy Sigma loses in telephoto reach, it gains in widest available aperture
Occupying a unique spot in the marketplace, this chunky Sigma lens combines a respectable telephoto zoom range with a wide f/2.8 aperture that remains constant throughout. As such, it’s two f/stops faster than typical 70-300mm f/4-5.6 telephoto zooms at the long end of their zoom range. The difference in aperture width is even more apparent when compared to the lenses on test that stretch to 500mm or 600mm at f/6.3 but, then again, you’re limited to about half the telephoto reach.
Like the new Sigma 150600mm, this ‘Sport’ lens has weather seals, a focus range limiter, dual-mode (but older generation) stabiliser, and customisation options that come courtesy of an optional USB dock. The lenses are almost identical in size, but this one has an internal zoom mechanism so it doesn’t increase in length at greater zoom settings. It’s heavier, at 3.39kg compared with 2.86kg, but has the same 105mm filter thread.
This lens matches the Sigma 150-600mm S in having two FLD elements, but has only one SLD element. Even so, it delivers excellent image quality throughout the zoom range. In our tests, the stabiliser gave a benefit of about three stops.