The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 16-35mm F2.8L III and the Sigma 12-24mm F4.5-5.6 II DG HSM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Canon 16-35mm F2.8L III is the longer of the two lenses at 128mm. The Sigma 12-24mm F4.5-5.6 II DG HSM with a length of 120mm, is 8mm shorter. Besides being longer, the Canon 16-35mm F2.8L III also has a larger diameter of 89mm compared to the Sigma 12-24mm F4.5-5.6 II DG HSM's 87mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Sigma 12-24mm F4.5-5.6 II DG HSM weighs 670g, 15% (120g) lighter than the Canon 16-35mm F2.8L III's weight of 790g.
Below you can find the dimension and weight table of the Wideangle Zoom Lenses in Canon EF Mount for size comparison purposes.
Ultra-Wideangle Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Canon 16-35mm F2.8L III and the Sigma 12-24mm F4.5-5.6 II DG HSM 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 12-24mm F4.5-5.6 II DG HSM is also available in Sigma SA and Nikon F (FX) mounts.
Focal Range
Canon 16-35mm F2.8L III has a focal range of 16-35mm and
2.2X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
25.6 - 56mm.
On the other hand, the Sigma 12-24mm F4.5-5.6 II DG HSM has a focal range of 12-24mm and 2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 19.2 - 38.4mm.