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 30mm F1.4 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. Pentax D FA 24-70mm F2.8 ED SDM WR is the longer of the two lenses at 110mm. The Sigma 30mm F1.4 EX DC HSM with a length of 59mm, is 51mm shorter. Besides being longer, the Pentax D FA 24-70mm F2.8 ED SDM WR also has a larger diameter of 89mm compared to the Sigma 30mm F1.4 EX DC HSM's 77mm 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 30mm F1.4 EX DC HSM weighs 430g, 45% (357g) lighter than the Pentax D FA 24-70mm F2.8 ED SDM WR's weight of 787g.
Lens Mounts
The Pentax D FA 24-70mm F2.8 ED SDM WR has the Pentax KAF3 lens mount whereas the Sigma 30mm F1.4 EX 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.
Sigma 30mm F1.4 EX DC HSM is also available in Canon EF-S , Nikon F (DX), Four Thirds, Sony Alpha and Sigma SA 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 30mm F1.4 EX DC HSM is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of 45mm when used on a APS-C / DX format camera.
