The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 24mm F1.8 EX DG and the Sigma 20mm F1.4 DG HSM A 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, which means it is 465g (48%) lighter than the Sigma 20mm F1.4 DG HSM A which has a weight of 950g.
Lens Mounts
Both the Sigma 24mm F1.8 EX DG and the Sigma 20mm F1.4 DG HSM A 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 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.
Sigma 20mm F1.4 DG HSM A is also available in Canon EF , Sigma SA and Leica L mounts.
Focal Range
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.
On the other hand, the 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.