introduced 2001 The image sensor in the EOS 1D and EOS D30 is smaller than a 35mm film frame. This means that the angle-of-view of an attached lens is narrower for the digital cameras than for film models. The result is that a lens attached to digital cameras appears to have a longer focal length than the same lens attached to a film camera. As a result, Canon has introduced the EF 16-35mm f2.8L USM lens as a replacement for the EF 17-35mm lens. The range may only have increased by 1mm, but at the wide-angle end this is much more significant than a 1mm increase at, say, 300mm. However, this is not just a lens for EOS digital cameras. It offers benefits for all EOS models:
• the first EF lens with three types of aspherical elements giving improved image quality
• two UD elements to provide effective correction for chromatic aberrations
• increased dust and water resistance
• inner focusing and ring USM for silent, high-speed autofocus
• circular diaphragm for better background blur (‘bokeh’)
• minimum focusing
The lens is compatible with Extension Tubes but not with Extenders. Close-up lenses 500 or 500D can be used and there is a rear drop-in filter slot. Focal length and maximum aperture:16-35mm 1:2.8
Lens construction: 14 elements in 10 groups
Diagonal angle-of-view: 108° 10'-63°
Focus adjustment: ring-type USM, inner focusing system, full-time manual focus
Closest focusing distance: 0.28 m/ 0.9ft., 0.22 x magnification
Zoom system: rotation type
Filter size: 77mm
Max. diameter x length, weight: 83.5 x 103mm, 600g | 
