The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron SP 15-30mm F2.8 Di VC USD G2 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. Tamron SP 15-30mm F2.8 Di VC USD G2 is the longer of the two lenses at 145mm. The Samyang 20mm F1.8 with a length of 88mm, is 57mm shorter. Besides being longer, the Tamron SP 15-30mm F2.8 Di VC USD G2 also has a larger diameter of 98mm compared to the Samyang 20mm F1.8'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. Samyang 20mm F1.8 weighs 497g, 55% (613g) lighter than the Tamron SP 15-30mm F2.8 Di VC USD G2's weight of 1110g.
Lens Mounts
Both the Tamron SP 15-30mm F2.8 Di VC USD G2 and the Samyang 20mm F1.8 has the same Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (FX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Tamron SP 15-30mm F2.8 Di VC USD G2 is also available in the Canon EF mount.
Samyang 20mm F1.8 is also available in Canon EF , Canon EF-M, Fujifilm X, Micro Four Thirds, Pentax KAF, Samsung NX, Sony Alpha and Sony E mounts.
Focal Range
Tamron SP 15-30mm F2.8 Di VC USD G2 has a focal range of 15-30mm and
2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
22.5 - 45mm.
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.