The Canon 24-70mm f/4 L USM IS is a high-performance, medium-length, L-class zoom lens with USM autofocus and IS image stabilization. The 24-70mm focal length is great for mid-range subjects such as portraits, candids, product and general purpose photography. It is lighter and shorter than its f/2.8 cousin and is a good choice when an f/2.8 aperture is not necessary. The lens has a built-in macro function which locks the ideal placement of elements within the lens and allows shooting at magnification up to 0.7 X.
This lens is often compared with the Canon 24-105mm f/4 USM IS and Canon 24-70mm f/2.8 L USM II.
Fast Aperture: The large aperture of this lens helps give you fast shutter speeds in available light and excellent depth-of-field control.
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.