Lens review

Canon EF-S 10-22 mm f/3.5-4.5 USM

8. Vignetting

In this category we did not expect good results - the laws of physics cannot be changed. One cannot make a large size wide angle lens, which would not show light, fall off in the corners of the frame.

The vignetting is therefore a serious problem in the whole focal lengths' range but the greatest is for 10 mm. In this case, with a wide open aperture, the light fall off reaches as much as 47% (-1.8 the value of the diaphragm). Stopping down the lens to f/4.0 makes the values decrease to 25% and to f/8.0 to 20%. For a 17 mm focal length and the f/4.0 diaphragm the light fall off in the corners of the frame was 41%. Stopping down to f/5.6 diminishes the problem to 22% and to f/8.0 to over just 10-20%. We observed almost the same situation for 22 mm. Here with a wide open aperture, vignetting values of 41%., drop to 24% for f/5.6 and to 17% for f/8.0.

To sum it up, the vignetting in the Canon 10-22 mm is big, even stopping down the lens for two or three stops does not make the results acceptable. This would be intolerable for regular lenses, but such a specific lens as the Canon 10-22 mm can be forgiven. If we wanted to decrease the vignetting, while still maintaining the wide angle and the aperture/light (???) aperture, the lens designers would have to increase the size of the lens, which would not be acceptable for most users.