EF17-40mm f/4L USM Concept of development
Feature 1:
Ultrawide-angle zoom
Feature 2:
Ultrahigh-image quality
Feature 3:
Silent, high-speed AF
Feature 4:
Excellent dust-and-moisture-proof construction
Feature 5:
Outstanding operational ease
Feature 6: Environmentally friendly lead-free glasses
Others
Improving Compatibility of EF lenses to Digital Photography
Depth of Field Data for EF17-40mm f/4L USM