Product Description

The Canon EF 17-40mm f/4L USM is a professional-grade wide-angle zoom lens designed for photographers seeking superior optical performance in a lightweight, rugged body. With a constant f/4 aperture throughout the zoom range, this lens delivers consistent exposure and sharp results, ideal for expansive landscapes, interiors, and group shots. As part of Canon’s prestigious L-series, it boasts dust- and moisture-resistant construction for reliability in outdoor and demanding environments. Its ring-type Ultrasonic Motor (USM) ensures fast and near-silent autofocus, along with full-time manual focusing. Whether youre using a full-frame or APS-C Canon body, this lens remains one of the most dependable wide-angle zooms available.

Specifications 

• Focal Length: 17–40mm

• Maximum Aperture: f/4 (constant throughout zoom range)

• Minimum Aperture: f/22

• Lens Mount: Canon EF

• Format Compatibility: Full-frame and APS-C DSLR

• Angle of View: 104° to 57°

• Lens Construction: 12 elements in 9 groups

• Special Elements: 3 Aspherical lenses, 1 Super UD element

• Diaphragm Blades: 7 (nearly circular for smooth bokeh)

• Autofocus Motor: Ring-type Ultrasonic Motor (USM)

• Focus Override: Full-time manual focus available

• Minimum Focusing Distance: 0.28 meters (11 inches)

• Maximum Magnification: 0.24x

• Filter Thread Size: 77mm

• Dimensions (ø × L): Approx. 83.5 x 96.8 mm

• Weight: Approx. 500 grams

• Weather Sealing: Yes (except front element, recommended with filter)

• Release Year: 2003