The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 24-70mm F2.8 II and the Samyang 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. Sigma 24-70mm F2.8 II is the longer of the two lenses at 122mm. The Samyang 14mm F2.8 with a length of 96mm, is 26mm shorter. Besides being longer, the Sigma 24-70mm F2.8 II also has a larger diameter of 88mm compared to the Samyang 14mm F2.8's 87mm 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 14mm F2.8 weighs 552g, 24% (183g) lighter than the Sigma 24-70mm F2.8 II's weight of 735g.
Lens Mounts
The Sigma 24-70mm F2.8 II has the Sony E lens mount whereas the Samyang 14mm F2.8 has the Sony Alpha lens mount. Some of the latest released cameras that are compatible with these mounts are Sony FX5, Sony A7R VI and Sony A7 V for the Sony E Mount and Sony A99 II, Sony A68 and Sony A77 II for the Sony Alpha Mount.
Sigma 24-70mm F2.8 II is also available in the Leica L mount.
Samyang 14mm F2.8 is also available in Canon EF , Nikon F (FX), Four Thirds, Pentax KAF, Sony E and Samsung NX mounts.
Focal Range
Sigma 24-70mm F2.8 II has a focal range of 24-70mm and
2.9X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
36 - 105mm.
On the other hand, the Samyang 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.