The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 20mm F1.8 and the Tamron 35mm F1.8 Di VC USD 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 20mm F1.8 is the longer of the two lenses at 88mm. The Tamron 35mm F1.8 Di VC USD with a length of 81mm is 7mm shorter. Besides being longer, the Samyang 20mm F1.8 also has a larger diameter of 83mm compared to Tamron 35mm F1.8 Di VC USD's 80mm 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. Tamron 35mm F1.8 Di VC USD weighs 450g, 9% (47g) lighter than the Samyang 20mm F1.8's weight of 497g.
Below you can find the dimension and weight table of the 'Wideangle Prime Lenses in Nikon F (FX) Mount for size comparison purposes.
Wideangle Prime Lenses in Nikon F (FX) Mount for Size Comparison
Lens Mounts
Both Samyang 20mm F1.8 and Tamron 35mm F1.8 Di VC USD 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.
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.
Tamron 35mm F1.8 Di VC USD is also available in Canon EF and Sony Alpha mounts.
Focal Range
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 an 35mm (FF) equivalent of 30mm.
Tamron 35mm F1.8 Di VC USD is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 52.5mm.