The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 14-24mm F2.8 DG HSM and the Canon 17-40mm f4.0L USM for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sigma 14-24mm F2.8 DG HSM is the longer of the two lenses at 135mm. The Canon 17-40mm f4.0L USM with a length of 97mm is 38mm shorter. Besides being longer, the Sigma 14-24mm F2.8 DG HSM also has a larger diameter of 96mm compared to Canon 17-40mm f4.0L USM's 84mm diameter.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Canon 17-40mm f4.0L USM weighs 500g, 56% (650g) lighter than the Sigma 14-24mm F2.8 DG HSM's weight of 1150g.
Below you can find the dimension and weight table of the 'Wideangle Zoom Lenses in Canon EF Mount for size comparison purposes.
Wideangle Zoom Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both Sigma 14-24mm F2.8 DG HSM and Canon 17-40mm f4.0L USM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Sigma 14-24mm F2.8 DG HSM is also available in Nikon F (FX) and Sigma SA mounts.
Focal Range
Sigma 14-24mm F2.8 DG HSM has a focal range of 14-24mm and 1.7X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 22.4 - 38.4mm.
Canon 17-40mm f4.0L USM has a focal range of 17-40mm and 2.4X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 27.2 - 64mm.