The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 24mm F3.5 DG DN C and the Samyang 20mm F1.8 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. Samyang 20mm F1.8 is the longer of the two lenses at 88mm. The Sigma 24mm F3.5 DG DN C with a length of 49mm, is 39mm shorter. Besides being longer, the Samyang 20mm F1.8 also has a larger diameter of 83mm compared to the Sigma 24mm F3.5 DG DN C's 64mm 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 F3.5 DG DN C weighs 225g, which means it is 272g (54%) lighter than the Samyang 20mm F1.8 which has a weight of 497g.
Filter Threads
The Sigma 24mm F3.5 DG DN C has a filter size of 55mm whereas the Samyang 20mm F1.8 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 55mm filters that we recommend you to consider for the Sigma 24mm F3.5 DG DN C:
And these are the 77mm filters that we recommend for the Samyang 20mm F1.8:
Lens Mounts
Both the Sigma 24mm F3.5 DG DN C and the Samyang 20mm F1.8 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 24mm F3.5 DG DN C is also available in Leica L mount.
Samyang 20mm F1.8 is also available in Canon EF , Canon EF-M, Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF, Samsung NX and Sony Alpha mounts.
Focal Range
Sigma 24mm F3.5 DG DN C 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 Samyang 20mm F1.8 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.