The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 10-20mm F4-5.6 EX DC HSM and the Rokinon 14mm f2.8 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. Rokinon 14mm f2.8 is the longer of the two lenses at 96mm. The Sigma 10-20mm F4-5.6 EX DC HSM with a length of 81mm, is 15mm shorter. Besides being longer, the Rokinon 14mm f2.8 also has a larger diameter of 87mm compared to the Sigma 10-20mm F4-5.6 EX DC HSM's 84mm 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. Sigma 10-20mm F4-5.6 EX DC HSM weighs 470g, which means it is 82g (14%) lighter than the Rokinon 14mm f2.8 which has a weight of 552g.
Lens Mounts
Both the Sigma 10-20mm F4-5.6 EX DC HSM and the Rokinon 14mm f2.8 has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A68, Sony A77 II and Sony A58.
Sigma 10-20mm F4-5.6 EX DC HSM is also available in the Canon EF , Four Thirds, Pentax KAF, Sigma SA and Nikon F (DX) mounts.
Rokinon 14mm f2.8 is also available in Canon EF , Nikon F (FX), Four Thirds, Pentax KAF and Samsung NX mounts.
Focal Range
Sigma 10-20mm F4-5.6 EX DC HSM has a focal range of 10-20mm and
2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
15-30mm when used on a APS-C / DX format camera.
On the other hand, the Rokinon 14mm f2.8 is a prime lens with fixed focal lenght of 14mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 21mm.
