Lens review

Canon EF 55-200 mm f/4.5-5.6 II USM

8. Vignetting

The Canon 55-200 mm performs very well in this category. The reason could be its poor aperture. Even at open aperture the light fall off in the corners of the frame is never higher than 20%. A slight stopping down of the lens makes the vignetting results decrease to an acceptable level of 10%.

At 55 mm and f/4.5 the light fall off is 17% (0.54 the value of the diaphragm) and at f/5.6 it is only 9.9% and that is 0.30 the value of the aperture.

At 100 mm, and with the open aperture of f/5.0, the vignetting values are 11.5% (0.35 the value of the diaphragm) and at f/5.6 it is only 7.1% (0.22 the value of the diaphragm).

At the 200 mm focal length and f/5.6 the light fall off is 14.2% (0.44 the value of the diaphragm) and at f/8 it is only 5.5% (0.16 the value of the diaphragm).