The Canon EF-S 10-22mm f/3.5-4.5 USM is a wide-angle lens produced starting from 2004 and characterized by a focus that uses an ultrasonic AF motor (Ring-USM) and is very easy to handle thanks to its low weight (it weighs approximately 385 grams), but lacks automatic image stabilization and macro settings . Among the main advantages of this product we certainly find the excellent sharpness of the images thanks also to low distortion and a high level of resistance to flare in backlit conditions. The optimal aperture to obtain maximum sharpness in photos taken with the Canon EF-S 10-22mm f/3.5-4.5 USM is from f/5.6 to f/8 b> (particularly recommended at 22 millimetres) and the use of slim filters is recommended as the vignetting effect is increased especially at 10 millimetres. Among the characteristics that represent small disadvantages we find the high chromatic aberration especially at 10 millimeters even if it does not significantly affect it in normal conditions of use. All this makes it a lens not recommended for close-up photographs as it offers a maximum magnification of x0.17, but it is particularly suitable for any other use as it constantly manages to express its great potential with a high quality of colors and details present in the photos taken. The Canon EF-S 10-22 mm f/3.5-4.5 USM is a lens perfectly compatible with Canon EF APS-C reflex models.