The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 30mm F1.4 DC HSM and the HD Pentax-D FA 50mm F1.4 SDM AW 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 30mm F1.4 DC HSM with a length of 63mm, is 43mm shorter. Besides being longer, the HD Pentax-D FA 50mm F1.4 SDM AW also has a larger diameter of 80mm compared to the Sigma 30mm F1.4 DC HSM's 74mm 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 DC HSM weighs 435g, which means it is 475g (52%) lighter than the HD Pentax-D FA 50mm F1.4 SDM AW which has a weight of 910g.
Lens Mounts
The Sigma 30mm F1.4 DC HSM has the Canon EF lens mount whereas the HD Pentax-D FA 50mm F1.4 SDM AW 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 30mm F1.4 DC HSM is also available in the Nikon F (DX) and Sigma SA mounts.
Focal Range
Sigma 30mm F1.4 DC HSM is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of
48mm when used on a APS-C / DX format camera.
On the other hand, the 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.
