Features:
Lightweight thanks to the magnesium alloy
Ultrasonic autofocus motor
Two-mode image stabilisation: dual-axis camera movement correction or vertical axis only (for panning)
AF-Stop function switches off autofocus when an obstruction appears
Full-time manual focusing
4-stop Image Stabilizer - Fluorite, UD and Super UD (Ultra-low Dispersion) lens elements to minimise aberrations and for sharp, high-contrast images.
Super Spectra coatings reduce ghosting and flare.
Circular aperture produces attractive background bokeh.
Compatible with Canon EF 1.4x II and EF 2x II teleconverters (not included)
Good dust and moisture resistance