The Canon EF 17-40mm f4L USM is a professional L-series zoom lens that spans a versatile wide-angle range. With a constant f/4 aperture, durable construction, and advanced optics, it’s ideal for landscapes, architecture, and travel photography.

Optical Performance

This lens uses one Super UD element and three aspherical elements to reduce chromatic and spherical aberrations. As a result, it delivers high sharpness, clarity, and accurate colors. Additionally, Canon’s Super Spectra coating minimizes flare and ghosting, ensuring strong contrast even in bright lighting conditions.

Autofocus and Handling

The ring-type Ultrasonic Motor (USM) and internal focusing system provide quick, precise, and silent autofocus. You can also take advantage of full-time manual focus for greater control. The rounded seven-blade diaphragm creates smooth, pleasing bokeh, enhancing selective focus and depth-of-field effects.

Durability and Design

Built for professional use, the lens features weather sealing to resist dust and moisture, making it reliable in tough conditions. In addition to the front 77mm filter ring, it includes a rear holder that accepts up to three cut gel filters, offering more creative flexibility.