Canon EF 17-40mm f/4L USM lens, (tested with cropped-frame APS-C body)

11th November 2011

Written by Gordon Laing

Samples

with Canon EOS 400D / XTi

The following images were taken with the Canon EF 17-40mm f/4L USM lens using the Canon EOS 400D / XTi. Each image was recorded using the Large Fine JPEG mode and Standard Picture Style, while metering was set to Evaluative. The individual file size, exposure mode, shutter speed, aperture, ISO and lens details are listed for each image.

The crops are taken from the original files, reproduced at 100% and saved in Adobe Photoshop CS2 as JPEGs with the Very High quality preset, while the resized full images were made in Photoshop CS2 and saved with the High quality preset. The three crops are typically taken from far left, central and far right portions of each image. To see examples of the EF 17-40mm mounted on a full-frame body, visit the Gallery section of our 17-40mm with Canon EOS 5D review.

Landscape: 3.45MB, Program, 1/200, f10, ISO 100, 17-40mm at 17mm (equivalent to 27mm)

Fitted onto a cropped-frame body like the Canon 400D / XTi, the 17-40mm offers a general purpose range and could be used as a replacement for the kit lens.

Here it’s zoomed-out to 17mm, offering an equivalent of 27mm. The crops are packed with detail, although some areas at the far edges weren’t pin-sharp.

Portrait: 2.59MB, Aperture Priority, 1/1000, f4, ISO 100, 17-40mm at 40mm (equivalent to 64mm)

If you’re thinking of using the EF 17-40mm as a general-purpose replacement for the kit lens, you’ll miss out a little when zoomed-in.

That said, you can still take portrait shots with blurred backgrounds. We took this zoomed into the maximum focal length of 40mm, working at an equivalent of 64mm, with the aperture wide open. The crops are sharp and detailed and the background is certainly blurred a little.

Tree: 5.65MB, Program, 1/160, f9, ISO 200, 17-40mm at 17mm (equivalent to 27mm)

				Here’s another shot with the 17-40mm on the 400D / XTi zoomed-out to its widest focal length. The lens is clearly capable of resolving plenty of detail in the middle, but our sample softened in the extremes, which is a little disappointing considering it’s corrected for a full-frame body. We may have a poor copy, but it’s worth realising the 17-40mm’s ‘L’ specification doesn’t guarantee perfection.