The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 20mm F1.8 G and the Samyang 16mm f2.0 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. Samyang 16mm f2.0 is the longer of the two lenses at 89mm. The Sony FE 20mm F1.8 G with a length of 85mm, is 4mm shorter. Besides being longer, the Samyang 16mm f2.0 also has a larger diameter of 83mm compared to the Sony FE 20mm F1.8 G's 74mm diameter.
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, which means it is 210g (36%) lighter than the Samyang 16mm f2.0 which has a weight of 583g.
The Sony FE 20mm F1.8 G has the Sony E lens mount whereas the Samyang 16mm f2.0 has the Four Thirds lens mount. Some of the latest released cameras that are compatible with these mounts are Sony A7R V, Sony FX30 and Sony A7 IV for the Sony E Mount and , and for the Four Thirds Mount.
Samyang 16mm f2.0 is also available in Canon EF , Canon EF-M, Fujifilm X, Nikon F (DX), Micro Four Thirds, Pentax KAF, Sony Alpha, Sony E and Samsung NX mounts.
Sony FE 20mm F1.8 G 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.
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.