The Canon 24-105mm f/4 L USM IS lens is a medium-length, L-class telephoto zoom lens with USM autofocus zoom lens and IS image stabilization. The mid-range, 24-105mm focal length is well suited to portraits, candids, travel and general purpose photography. The f/4 aperture is available constantly through the entire zoom range. Weighing 670 grams, the lens is easy to carry for long periods and to use hand-held. It uses Canon Image Stabilizer technology to help steady camera shake.
This lens is often compared with the Canon 24-70mm f/4 USM IS and Canon 24-70mm f/2.8 L USM II.
USM: Canon USM ultrasonic autofocus is faster and quieter than mechanical autofocus systems.
IS: Canon IS image stabilization helps to steady your pictures and reduce blur from camera shake.