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 10-24mm f3.5-4.5 II LD 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. Samyang 20mm F1.8 is the longer of the two lenses at 88mm. The Tamron 10-24mm f3.5-4.5 II LD with a length of 84mm, is 4mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 83mm.
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. Tamron 10-24mm f3.5-4.5 II LD weighs 406g, 18% (91g) lighter than the Samyang 20mm F1.8's weight of 497g.
Filter Threads
Both the Samyang 20mm F1.8 and the Tamron 10-24mm f3.5-4.5 II LD have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Samyang 20mm F1.8 and the Tamron 10-24mm f3.5-4.5 II LD has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A99 II, Sony A68 and Sony A77 II.
Samyang 20mm F1.8 is also available in the Canon EF , Canon EF-M, Fujifilm X, Micro Four Thirds, Nikon F (FX), Pentax KAF, Samsung NX and Sony E mounts.
Tamron 10-24mm f3.5-4.5 II LD is also available in Canon EF , Nikon F (DX), Pentax KAF and Canon EF 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 a 35mm (FF) equivalent of
30mm.
On the other hand, the Tamron 10-24mm f3.5-4.5 II LD has a focal range of 10-24mm and 2.4X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 15-36mm when used on a APS-C / DX format camera.