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 DN A and the Sony FE 20mm F1.8 G for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Sigma 20mm F1.4 DG DN A is the longer of the two lenses at 111mm. The Sony FE 20mm F1.8 G with a length of 85mm, is 26mm shorter. Besides being longer, the Sigma 20mm F1.4 DG DN A also has a larger diameter of 88mm compared to the Sony FE 20mm F1.8 G's 74mm diameter.
Below you can find a scaled side-by-side image of Sigma 20mm F1.4 DG DN A and Sony FE 20mm F1.8 G to get a better idea of how their sizes compare in real life.
Comparison image of the Sigma 20mm F1.4 DG DN A and the Sony FE 20mm F1.8 G Size and Weight The 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. Sony FE 20mm F1.8 G weighs 373g, 41% (262g) lighter than the Sigma 20mm F1.4 DG DN A's weight of 635g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Sony E Mount for size comparison purposes.
Wideangle Prime Lenses in Sony E Mount for Size Comparison
Lens Mounts
Both the Sigma 20mm F1.4 DG DN A and the Sony FE 20mm F1.8 G has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony ZV-E1, Sony A7R V and Sony FX30.
Sigma 20mm F1.4 DG DN A is also available in Leica L mount.
Focal Range
Both lenses have the same focal range of 20mm but while Sigma 20mm F1.4 DG DN A has the fastest aperture of F1.4, the Sony FE 20mm F1.8 G's widest aperture value is F1.8.