The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 10-20mm F3.5 EX DC HSM and the PENTAX15-30mm F2.8 ED WR 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. PENTAX15-30mm F2.8 ED WR is the longer of the two lenses at 144mm. The Sigma 10-20mm F3.5 EX DC HSM with a length of 88mm, is 56mm shorter. Besides being longer, the PENTAX15-30mm F2.8 ED WR also has a larger diameter of 99mm compared to the Sigma 10-20mm F3.5 EX DC 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 10-20mm F3.5 EX DC HSM weighs 520g, which means it is 520g (50%) lighter than the PENTAX15-30mm F2.8 ED WR which has a weight of 1040g.
Lens Mounts
The Sigma 10-20mm F3.5 EX DC HSM has the Canon EF lens mount whereas the PENTAX15-30mm F2.8 ED WR has the Pentax KAF3 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 Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount.
Sigma 10-20mm F3.5 EX DC HSM is also available in the Pentax KAF3 , Sony Alpha, Sigma SA and Nikon F (DX) mounts.
Focal Range
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.
On the other hand, the PENTAX15-30mm F2.8 ED WR has a focal range of 15-30mm 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 22.5 - 45mm.
