The L-series is Canon's flagship professional lens range. The iconic red line represents the best in precision-designed EF optics.
A ring-type ultrasonic motor drives autofocus extremely quickly, and in near silence.
The f/4 maximum aperture of this lens is fixed throughout the lens' focal-length range, so shutter speeds will not change as the lens is zoomed.
IS permits the use of shutter speeds up to three stops slower than normal, with no perceptible increase in image blur from camera shake.