The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 24mm F1.4 DG HSM A and the Nikon 20mm f2.8D for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sigma 24mm F1.4 DG HSM A is the longer of the two lenses at 90mm. The Nikon 20mm f2.8D with a length of 43mm is 47mm shorter. Besides being longer, the Sigma 24mm F1.4 DG HSM A also has a larger diameter of 85mm compared to Nikon 20mm f2.8D's 69mm diameter.
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Nikon 20mm f2.8D weighs 270g, 59% (395g) lighter than the Sigma 24mm F1.4 DG HSM A's weight of 665g.
Below you can find the dimension and weight table of the 'Wideangle Prime Lenses in Nikon F (FX) Mount for size comparison purposes.
Wideangle Prime Lenses in Nikon F (FX) Mount for Size Comparison
Lens Mounts
Both Sigma 24mm F1.4 DG HSM A and Nikon 20mm f2.8D 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 F1.4 DG HSM A is also available in Canon EF , Sigma SA and Leica L mounts.
Focal Range
Sigma 24mm F1.4 DG HSM A 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 an 35mm (FF) equivalent of 36mm.
Nikon 20mm f2.8D 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 an 35mm (FF) equivalent of 30mm.