Canon EF 17-40mm f/4L USM Lens

Spanning a versatile wide-angle range - the EF 17-40mm f/4L USM Lens is a Canon L-series zoom featuring a constant f/4 maximum aperture along with a sophisticated optical design and durable construction One Super UD element is featured - along with three aspherical elements - which help to reduce both chromatic and spherical aberrations in order to realize high sharpness - clarity - and color accuracy A Super Spectra coating has also been applied to suppress flare and ghosting for improved contrast in difficult lighting conditions Complementing the imaging capabilities - this wide-angle zoom also features a ring-type USM and internal focusing mechanism to afford quick - quiet - and accurate autofocus performance - as well as full-time manual focus override Additionally - this lens is weather-sealed for use in trying environmental conditions

Features: EF-Mount Lens/Full-Frame Format, Aperture Range: f/4 to f/22, One Super Ultra-Low Dispersion Element, Rounded 7-Blade Diaphragm, Super Spectra Coating, Ring-Type Ultrasonic Motor AF System, Weather-Sealed Construction, Three Aspherical Element

Focal Length: 17 to 40mm

Maximum Aperture: f/4

Minimum Aperture: f/22

Lens Mount: Canon EF

Lens Format Coverage: Full-Frame

Angle of View: 104° to 57° 30'

Minimum Focus Distance: 11.02-inch / 28 cm

Maximum Magnification: 0.24x

Optical Design: 12 Elements in 9 Groups

Diaphragm Blades: 7 - Rounded

Focus Type: Autofocus

Image Stabilization: No

Filter Size: 77 mm (Front)Gel Filter (Rear)

Dimensions (ø x L): 3.29 x 3.81-inch / 83.57 x 96.77 mm

Length at Maximum Extension: 3.82-inch / 97 mm

Weight: 1.1 lb / 500 g