Lens review

Sigma 18-50 mm f/2.8-4.5 DC OS HSM

6. Distortion

In the lenses whose focal lengths start at 17-18 mm and end at 50-55 mm distortion bothers us the most at the shortest aperture, where we usually have a noticeable barrel of about 3-4%. Sigma performs well compared to its rivals, as at 18 mm its distortion amounts to -2.98%, which is one of the smallest results in the class. Quite properly corrected distortion at the widest angle took its toll at longer focal lengths. In a typical equipment of this class, when extending the focal length, distortion becomes smaller in a fast way and it’s often on a level much lower than 1%. Sigma at 30 mm reaches the level 1.12% and at 50 mm 0.99%. Although results these aren’t really bothering, you’d want slightly smaller ones.