The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 24-35mm F2 DG HSM A and the Canon 20-35mm f3.5-4.5 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 24-35mm F2 DG HSM A is the longer of the two lenses at 123mm. The Canon 20-35mm f3.5-4.5 USM with a length of 69mm is 54mm shorter. Besides being longer, the Sigma 24-35mm F2 DG HSM A also has a larger diameter of 88mm compared to Canon 20-35mm f3.5-4.5 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 20-35mm f3.5-4.5 USM weighs 340g, 63% (601g) lighter than the Sigma 24-35mm F2 DG HSM A's weight of 941g.
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
Both Sigma 24-35mm F2 DG HSM A and Canon 20-35mm f3.5-4.5 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 24-35mm F2 DG HSM A is also available in Nikon F (FX) and Sigma SA mounts.
Sigma 24-35mm F2 DG HSM A has a focal range of 24-35mm and 1.5X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 38.4 - 56mm.
Canon 20-35mm f3.5-4.5 USM has a focal range of 20-35mm and 1.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 32 - 56mm.