The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 20mm F1.8 EX DG RF and the Samyang 16mm f2.0 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 F1.8 EX DG RF is the longer of the two lenses at 90mm. The Samyang 16mm f2.0 with a length of 89mm, is 1mm shorter. Besides being longer, the Sigma 20mm F1.8 EX DG RF also has a larger diameter of 89mm compared to the Samyang 16mm f2.0's 83mm 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 20mm F1.8 EX DG RF weighs 520g, which means it is 63g (10%) lighter than the Samyang 16mm f2.0 which has a weight of 583g.
Filter Threads
The Sigma 20mm F1.8 EX DG RF has a filter size of 82mm whereas the Samyang 16mm f2.0 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 F1.8 EX DG RF:
And these are the 77mm filters that we recommend for the Samyang 16mm f2.0:
Lens Mounts
Both the Sigma 20mm F1.8 EX DG RF and the Samyang 16mm f2.0 has the same Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (DX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Sigma 20mm F1.8 EX DG RF is also available in Canon EF , Pentax KAF, Sony Alpha and Sigma SA mounts.
Samyang 16mm f2.0 is also available in Canon EF , Canon EF-M, Fujifilm X, Four Thirds, Micro Four Thirds, Pentax KAF, Sony Alpha, Sony E and Samsung NX mounts.
Focal Range
Sigma 20mm F1.8 EX DG RF 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.
On the other hand, the Samyang 16mm f2.0 is a prime lens with fixed focal lenght of 16mm which has an effective (full-frame 35mm equivalent) focal range of 24mm when used on a APS-C / DX format camera.