The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 10-18mm f4.5-5.6 IS STM and the Sigma 12-24mm F4.5-5.6 EX 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. Sigma 12-24mm F4.5-5.6 EX DG HSM is the longer of the two lenses at 103mm. The Canon 10-18mm f4.5-5.6 IS STM with a length of 72mm, is 31mm shorter. Besides being longer, the Sigma 12-24mm F4.5-5.6 EX DG HSM also has a larger diameter of 87mm compared to the Canon 10-18mm f4.5-5.6 IS STM's 75mm 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. Canon 10-18mm f4.5-5.6 IS STM weighs 240g, which means it is 360g (60%) lighter than the Sigma 12-24mm F4.5-5.6 EX DG HSM which has a weight of 600g.
Lens Mounts
The Canon 10-18mm f4.5-5.6 IS STM has the Canon EF-S lens mount whereas the Sigma 12-24mm F4.5-5.6 EX DG HSM has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are Canon T8i, Canon 90D and Canon SL3 for the Canon EF-S Mount and Blackmagic URSA 12K LF, Z CAM E2-F6 II 6K and Z CAM E2-S6 II 6K for the Canon EF Mount.
Sigma 12-24mm F4.5-5.6 EX DG HSM is also available in Pentax KAF , Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Focal Range
Canon 10-18mm f4.5-5.6 IS STM has a focal range of 10-18mm and
1.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
16-28.8mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 12-24mm F4.5-5.6 EX 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.
