The type of photography that you are planning to use is an important decision factor. Here we have evaluated the HD Pentax-D FA 50mm F1.4 SDM AW and the Sigma 24-70mm F2.8 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. HD Pentax-D FA 50mm F1.4 SDM AW is the longer of the two lenses at 106mm. The Sigma 24-70mm F2.8 EX DG HSM with a length of 95mm, is 11mm shorter. On the other hand, the Sigma 24-70mm F2.8 EX DG HSM has a larger diameter of 89mm compared to the HD Pentax-D FA 50mm F1.4 SDM AW's 80mm 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 24-70mm F2.8 EX DG HSM weighs 790g, 13% (120g) lighter than the HD Pentax-D FA 50mm F1.4 SDM AW's weight of 910g.
Lens Mounts
Both the HD Pentax-D FA 50mm F1.4 SDM AW and the Sigma 24-70mm F2.8 EX DG HSM has the same Pentax KAF3 lens mount. Some of the latest released cameras that are compatible with the Pentax KAF3 lenses are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III.
Sigma 24-70mm F2.8 EX DG HSM is also available in Canon EF , Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Focal Range
HD Pentax-D FA 50mm F1.4 SDM AW is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
75mm.
On the other hand, the Sigma 24-70mm F2.8 EX DG HSM 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.
