The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 12-24mm F4.5-5.6 II DG HSM and the Sigma 10-20mm F3.5 EX DC HSM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Sigma 12-24mm F4.5-5.6 II DG HSM is the longer of the two lenses at 120mm. The Sigma 10-20mm F3.5 EX DC HSM with a length of 88mm, is 32mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 87mm.
The 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. Sigma 10-20mm F3.5 EX DC HSM weighs 520g, 22% (150g) lighter than the Sigma 12-24mm F4.5-5.6 II DG HSM's weight of 670g.
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 the Sigma 12-24mm F4.5-5.6 II DG HSM and the Sigma 10-20mm F3.5 EX DC 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.
Sigma 10-20mm F3.5 EX DC HSM is also available in Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
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.
Sigma 10-20mm F3.5 EX DC HSM has a focal range of 10-20mm and 2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 16-32mm when used on a APS-C / DX format camera.