This document is the user manual for Canon EF17-40mm f/4L USM lens, which introduces the features and characteristics of the lens, such as high-performance wide-angle zoom, high-speed and silent autofocus achieved by ultrasonic motor, and genuine circular aperture.
This manual explains safe handling of the EF 17-40mm f/4L USM lens, including precautions when moving the lens between cold and warm environments, protection against dust and water, and proper cleaning of electronic contacts. It also covers focus mode settings, infinity and infrared marks, and how to install filters and accessories.
Detailed specifications such as focal length, aperture, lens construction, minimum focusing distance, and dimensions are listed, along with recommended filter size, lens hood model, and country of origin. The guide includes step‑by‑step instructions for installing and removing the lens, setting focus modes, and using the lens with infrared film. This manual is written in Chinese.
| Focal length / maximum aperture | 17-40mm f/4 |
|---|---|
| Lens construction | 9 groups, 12 elements |
| Minimum focusing distance | 0.28 m |
| Maximum magnification | 0.24x |
| Maximum diameter and length | 83.5 x 96.8 mm |
| Weight | 4759 |
| Filter size | 77 mm |
| Lens hood model | EW-83E |
| Lens cap model | E-77U |
Place the lens in a sealed plastic bag before moving, let it warm gradually, and avoid exposing it directly to sunlight or high temperatures.
A 77 mm filter (Canon protective filter) is recommended.
The lens has a maximum aperture of f/4.