Sigma 70-300mm f/4-5.6 DG OS - £300/ $359
It might seem that the newer 70-300mm OS lens is simply Sigma's older model with an optical stabiliser. In fact, it's completely different. But what you gain in a highly effective four-stop optical stabiliser, you lose elsewhere. This lens only has one SLD (Super Low Dispersion) element, not three, and the macro facility disappears altogether. Even so, it's a good trade-off – optical stabilisation has become a must-have feature for handheld telephoto shooting with effective focal lengths of up to 450mm.
Neither of Sigma's 70-300mm lenses have ultrasonic autofocus so, as with the APO version, this lens's focusing is fairly quick but quite noisy. Again, the front element rotates when it focuses, making filters such as circular polarisers tricky to use. Compared to Sigma's 70-300mm APO lens, the OS is 60g heavier, 4mm longer and has a larger filter thread (62mm, not 58mm).
In our tests, the stabiliser on this lens performed more consistently than the Sigma 50-200mm's. And even though the DG lacks the competing Sigma 70-300mm lens's APO label, chromatic aberration was even less noticeable. Sharpness improved slightly when we shot at the maximum aperture at 300mm too.
Lab test results
The Sigma 70-300mm puts in a good, consistent performance, with only the smallest drop in sharpness at full zoom.
This Sigma shows the least fringing in the test, with little to no signs at all focal lengths and across the frame.
At 135mm the Sigma shows the least pinch distortion in the test; at 70mm and 300mm distortion was average.
Image quality verdict
The Sigma 70-300mm produces the best results in the test across the board for sharpness, colour fringing and distortion.
Read the full Sigma 70-300mm f/4-5.6 DG OS review