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 Samyang 24mm f1.4 for their suitability to various photography scenarios:
Size and Weight Comparison
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. Samyang 24mm f1.4 weighs 580g, 8% (55g) 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 Lenses in Sony E Mount for Size Comparison
Filter Threads
The Sigma 20mm F1.4 DG DN A has a filter size of 82mm whereas the Samyang 24mm f1.4 has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 82mm filters that we recommend you to consider for the Sigma 20mm F1.4 DG DN A:
And these are the 77mm filters that we recommend for the Samyang 24mm f1.4:
Lens Mounts
Both the Sigma 20mm F1.4 DG DN A and the Samyang 24mm f1.4 has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony A9 III, Sony A7C Mark II and Sony A7CR.
Sigma 20mm F1.4 DG DN A is also available in Leica L mount.
Samyang 24mm f1.4 is also available in Canon EF , Nikon F (FX), Four Thirds, Pentax KAF, Sony Alpha and Samsung NX mounts.
Focal Range
Sigma 20mm F1.4 DG DN 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
36mm.
On the other hand, the Samyang 24mm f1.4 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.