The Canon EF 24-85mm f/3.5-4.5 USM is a standard zoom lens designed for the EOS SLR system, compatible with both Full Frame and APS-C format sensors. The optical design consists of 15 elements in 12 groups and includes one aspherical element aimed at reducing spherical aberrations and stabilizing sharpness throughout the focal range. The focusing system is driven by a ring-type ultrasonic motor (USM), which enables internal autofocus and offers full-time manual focus support, allowing manual adjustment without switching out of AF mode. The lens features a variable maximum aperture from f/3.5 to f/4.5, regulated by a 6-blade diaphragm. The barrel is constructed from high-resistance plastic materials with a metal bayonet mount, maintaining a total weight of approximately 380 grams. The minimum focusing distance is 0.5 meters across the entire zoom range, while the front filter diameter is 67 mm. The lens does not feature optical image stabilization and the front element does not rotate during focusing, facilitating the use of circular polarizers and graduated filters.