A good general purpose lens as with the EF 90-300 mm f/4,5-5,6 but including a USM
The EF 90-300mm f/4.5-5.6 USM is a lightweight compact telephoto zoom lens. It features a micro USM ultrasonic motor..
The optics of the EF 90-300mm f/4.5-5.6 USM are based on those of the EF 75-300mm f/4-5.6 III USM and the optical performance is similar. However, the AF drive pattern has been optimized for the EOS 300V, giving a faster AF speed. The communication speed between the lens and the camera is faster due to a new high-speed CPU. Also, a new AF algorithm has been developed. All the lens elements are manufactured from environmentally-friendly lead-free glass. A redesigned electromagnetic diaphragm (EMD) provides an aperture which is nearly circular at the widest settings. This gives an improved out-of-focus background effect. This lens features a micro USM (Ultrasonic Motor) motor which operates almost noiseless.