The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 21mm F1.4 ED AS UMC CS and the Samyang 16mm f2.0 for their suitability to various photography scenarios:
Size and Weight Comparison
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 Samyang 21mm F1.4 ED AS UMC CS with a length of 68mm is 21mm shorter. Besides being longer, the Samyang 16mm f2.0 also has a larger diameter of 83mm compared to Samyang 21mm F1.4 ED AS UMC CS's 64mm diameter.
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. Samyang 21mm F1.4 ED AS UMC CS weighs 275g, which means it is 308g (52%) lighter than the Samyang 16mm f2.0 which has a weight of 583g.
Below you can find the dimension and weight table of the 'Wideangle Prime Lenses in Fujifilm X Mount for size comparison purposes.
Wideangle Prime Lenses in Fujifilm X Mount for Size Comparison
Both Samyang 21mm F1.4 ED AS UMC CS and Samyang 16mm f2.0 has the same Fujifilm X lens mount. Some of the latest released cameras that are compatible with the Fujifilm X lenses are Fujifilm X-T5, Fujifilm X-H2 and Fujifilm X-H2S.
Samyang 21mm F1.4 ED AS UMC CS is also available in Canon EF-M , Micro Four Thirds and Sony E mounts.
Samyang 16mm f2.0 is also available in Canon EF , Canon EF-M, Nikon F (DX), Four Thirds, Micro Four Thirds, Pentax KAF, Sony Alpha, Sony E and Samsung NX mounts.
Samyang 21mm F1.4 ED AS UMC CS is a prime lens with fixed focal lenght of 21mm which has an effective (full-frame 35mm equivalent) focal range of 31.5mm when used on a APS-C / DX format camera. 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.