Lens review

Sigma 24-70 mm f/2.8 EX DG HSM

5. Chromatic aberration

When it comes to the chromatic aberration correction for the small sensor edge, the Zeiss lens was the shining example to be followed. In its case, at the shortest focal length the aberration level was 0.06%, so very low, and for longer focal lengths it decreased to the imperceptible level of about 0.03%. The performance of the Canon 24-70 mm was only a tad worse, because the level of the chromatic aberration oscillated between 0.04% and 0.07%. The Nikkor was weaker than its rivals, because in its case the aberration reached medium values at shorter focal lengths and was small at 70 mm.

The Sigma 24-70 mm performs here like the Nikkor, which can be seen on the graph above. The fewest aberration problems will be for the middle of the focal range, where it is low or imperceptible. Even the maximum level of this aberration, though, at the maximum aperture and extreme focal lengths reaching the level of 0.08-0.09%, cannot be a serious matter of concern. It’s still a borderline between low and medium levels so it won’t bother us a lot.

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When we proceed to the full frame corner, the aberration becomes far more visible. Here you can perceive it without any problems, as, from time to time, it approaches the level of 0.14% which we deem to be the borderline between medium and high levels. It’s worth remembering, though, that on full frame the Sigma is a very universal and fast zoom lens. Finding a good chromatic aberration correction for the combination of a wide field of view and a decent fastness has never been an easy task.

The edge of the FX frame
D3x, 24 mm, f/2.8	D3x, 45 mm, f/22.0