EF 17-40mm f/4L USM
Canon's three f/4 L-series zooms give the critical industrial, scientific or professional shooter image quality that matches their f/2.8 counterparts, but in a lighter and less-expensive package. The EF 17-40mm f/4L follows this path, essentially matching the 16-35mm f/2.8L II's optical quality, but at about half the price. This lens is a superb, "all-in-one" wide-angle choice for full-frame and EOS-1D shooters, covering everything from ultra-wide to standard wide-angle in one convenient – and sharp – package. Especially with the great high-ISO performance of today's D-SLRs, the f/4 option is a compelling one for critical photographers.
- Superb all-around wide-angle choice for full-frame EOS models, as well as EOS-1D cameras: one lens covers nearly all wide-angle needs
- Excellent choice for HD video, since it provides ultra-wide coverage at a fraction of the cost of exotic, ultra-wide lenses for traditional video cameras
- Applications include nearly anything where wide-angle coverage is needed: commercial shooting, photojournalism, real estate, industrial, government and military, and so on
- Can be used on small-sensor, APS-C size cameras (1.6x "crop factor" means it gives coverage equal to a 27–64mm lens)