The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax D FA 24-70mm F2.8 ED SDM WR and the Sigma 18-35mm F1.8 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 18-35mm F1.8 DC HSM is the longer of the two lenses at 121mm. The Pentax D FA 24-70mm F2.8 ED SDM WR with a length of 110mm, is 11mm shorter. On the other hand, the Pentax D FA 24-70mm F2.8 ED SDM WR has a larger diameter of 89mm compared to the Sigma 18-35mm F1.8 DC HSM's 78mm diameter.
Below you can find a scaled side-by-side image of Pentax D FA 24-70mm F2.8 ED SDM WR and Sigma 18-35mm F1.8 DC HSM to get a better idea of how their sizes compare in real life.
Comparison image of the Pentax D FA 24-70mm F2.8 ED SDM WR and the Sigma 18-35mm F1.8 DC HSM Size and Weight 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. Pentax D FA 24-70mm F2.8 ED SDM WR weighs 787g, which means it is 23g (2%) lighter than the Sigma 18-35mm F1.8 DC HSM which has a weight of 810g.
Lens Mounts
The Pentax D FA 24-70mm F2.8 ED SDM WR has the Pentax KAF3 lens mount whereas the Sigma 18-35mm F1.8 DC HSM has the Pentax KAF lens mount . Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Mono , Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and Pentax K-3 III Mono , Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Canon EF , Sony Alpha , Sigma SA and Nikon F (DX) mounts.
Focal Range
Pentax D FA 24-70mm F2.8 ED SDM WR has a focal range of 24-70mm and
2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
36 - 105mm .
On the other hand, the Sigma 18-35mm F1.8 DC HSM has a focal range of 18-35mm and 1.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27-52.5mm when used on a APS-C / DX format camera.
