The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 20mm F1.4 DG HSM A and the Sigma 24mm F1.8 EX DG 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 20mm F1.4 DG HSM A is the longer of the two lenses at 130mm. The Sigma 24mm F1.8 EX DG with a length of 83mm, is 47mm shorter. Besides being longer, the Sigma 20mm F1.4 DG HSM A also has a larger diameter of 91mm compared to the Sigma 24mm F1.8 EX DG's 84mm 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 24mm F1.8 EX DG weighs 485g, 48% (465g) lighter than the Sigma 20mm F1.4 DG HSM A's weight of 950g.
Lens Mounts
Both the Sigma 20mm F1.4 DG HSM A and the Sigma 24mm F1.8 EX DG has the same Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (FX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Sigma 20mm F1.4 DG HSM A is also available in Canon EF , Sigma SA and Leica L mounts.
Sigma 24mm F1.8 EX DG is also available in Canon EF , Four Thirds, Pentax KAF, Sony Alpha, Sigma SA, Canon EF, Pentax KAF, Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Focal Range
Sigma 20mm F1.4 DG HSM A is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
30mm.
On the other hand, the Sigma 24mm F1.8 EX DG is a prime lens with fixed focal lenght of 24mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 36mm.