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 50mm F2.8 EX DG Macro 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 50mm F2.8 EX DG Macro with a length of 67mm, is 39mm 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 50mm F2.8 EX DG Macro's 71mm 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 50mm F2.8 EX DG Macro weighs 320g, 64% (590g) lighter than the HD Pentax-D FA 50mm F1.4 SDM AW's weight of 910g.
Lens Mounts
The HD Pentax-D FA 50mm F1.4 SDM AW has the Pentax KAF3 lens mount whereas the Sigma 50mm F2.8 EX DG Macro has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Sigma 50mm F2.8 EX DG Macro is also available in Canon EF , Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Focal Range
Both lenses have the same focal range of
50mm but while HD Pentax-D FA 50mm F1.4 SDM AW has the fastest aperture of
F1.4, the Sigma 50mm F2.8 EX DG Macro's widest aperture value is
F2.8.