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 EX 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 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 Sigma 10-20mm F3.5 EX DC HSM with a length of 88mm, is 15mm 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 equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Sigma 10-20mm F3.5 EX DC HSM weighs 520g, 13% (80g) lighter than the Sigma 12-24mm F4.5-5.6 EX DG HSM's weight of 600g.
Lens Mounts
The Sigma 12-24mm F4.5-5.6 EX DG HSM has the Pentax KAF lens mount whereas the Sigma 10-20mm F3.5 EX DC HSM has the Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount and , and for the Pentax KAF3 Mount.
Sigma 12-24mm F4.5-5.6 EX DG HSM is also available in Canon EF , Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Sigma 10-20mm F3.5 EX DC HSM is also available in Canon EF , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
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 1.5x crop, it provides a 35mm (FF) equivalent of
18 - 36mm.
On the other hand, the 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 15-30mm when used on a APS-C / DX format camera.