Lens review

Canon EF-S 17-55 mm f/2.8 IS USM

6. Distortion

The previously tested Canon 17-85 IS USM performed very poorly in this category, for a 17 mm you could see a clear barrel distortion at a level of -5.7%. Since Canon's 17-55 IS USM has a smaller focal range it deals much better with geometrical deformations. With a maximum wide angle we observed a noticeable but not too big barrel distortion with a level of -2.47%.

The distortions decrease to the point of 24 mm where they reach minimum and almost to the zero level. Then they start increasing again and, at 30 mm, the distortion becomes pincushion and reaches a value of 1.06%. It keeps slowly increasing and for a 55 mm the results are 1.38%.