Canon EF 17-40mm f/4L USM
Versatile L-series ultra-wide angle zoom lens
Key Features
Lens Capabilities
Click the Links Below for Details
The Most Important Rings & Switches — Canon EF 17-40mm f/4L USM
| Ring / Switch / Control | Status | Note |
|---|---|---|
| Focus Ring | ✓ Present | |
| Zoom Ring | ✓ Present | |
| Aperture Ring | ✗ Not Present | |
| AF/MF Switch | ✓ Present | |
| Image Stabilisation Switch | ✗ Not Present | |
| Focus Limiter Switch | ✗ Not Present | |
| Function (L-Fn) Button | ✗ Not Present | |
| Zoom Lock Switch | ✗ Not Present | |
| Optical Image Stabilisation (OIS) | ✗ Not Present | |
| Weather Sealing | ✓ Present | Requires filter for full sealing |
How-to Use Canon EF 17-40mm f/4L USM
Welcome to the How-to section of the lens. In this Light & Composition University website, each page for a lens has a how-to section and a section for learning. The rings, switches and controls of each lens are placed differently between brands and models. The how-to section helps you operate the lens; however, if you are interested in learning photography, you also need to know what each control changes and why you would change it. Click the “Learn” or scroll down.
Learn & Master Photography with Canon EF 17-40mm f/4L USM
For over a decade, we have been teaching photography following a university standard. No one does it better than us. We have a selection of courses, diplomas, graduate and post-graduate programs, as well as some of our best-selling university press publications, to guide you in the best possible way for your lens. Enroll in the fundamentals and then move to the genres you want to master.
Technical Specification
| Focal Length | 17-40mm |
| Max Aperture | f/4 |
| Min Aperture | f/22 |
| Lens Construction | 12 elements in 9 groups |
| Diaphragm Blades | 7 |
| Min Focus Distance | 0.28m |
| Max Magnification | 0.25x |
| Filter Size | 77mm |
| Focus Motor | Ring USM |
| Weather Sealing | Yes |
| Weight | 500g |
| Dimensions | 83.5 x 96.8 mm |
