Canon EF 17-40mm f4L USM
The Canon EF 17-40 features Canon's L-series quality glass and is a very wide angle on both full frame cameras as well as crop sensor camera bodies. It has a maximum aperture of f/4 throughout all focal lengths. The USM motor equipped is quick, quiet, and accurate.
If you want a sharp, wide angle, L series lens and do not need f2.8 or Image Stabilization, this is a great choice and reasonably priced.
- Ultra wide angle zoom
- L series quality and sealing
- Internal focusing
- Ultrasonic focus motor
The Canon EF 17-40 f/4L lens is a very high quality lens with Canon’s L glass but at a moderate price. Whether on a cropped sensor or a full frame camera, 17-40 is an ultra wide angle zoom lens. It is Canon’s lightest L series lens and the smallest L zoom lens as well. While zooming from 17mm to 40mm the front element moves internally, meaning that it doesn’t extend outward. With a USM motor, the lens focuses very fast, quiet, and accurately.
I like using this lens to really exaggerate backgrounds. Especially on a full frame sensor at 17mm, you get a strong sense of perspective. At a maximum aperture of f/4 some situations could use a little more light, but that’s nothing some good ISO can’t help with! Wide open at f/4 there is noticeable vignetting on a full frame as well as less sharpness in the corners. Because the angle can be so wide, anything in the corners at 17mm will be a bit distorted.