The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 50mm F1.8 and the Sigma 15mm F2.8 EX DG Fisheye 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 15mm F2.8 EX DG Fisheye is the longer of the two lenses at 65mm. The Sony FE 50mm F1.8 with a length of 60mm, is 5mm shorter. Besides being longer, the Sigma 15mm F2.8 EX DG Fisheye also has a larger diameter of 74mm compared to the Sony FE 50mm F1.8's 69mm 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. Sony FE 50mm F1.8 weighs 186g, which means it is 184g (49%) lighter than the Sigma 15mm F2.8 EX DG Fisheye which has a weight of 370g.
Lens Mounts
The Sony FE 50mm F1.8 has the Sony E lens mount whereas the Sigma 15mm F2.8 EX DG Fisheye 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 15mm F2.8 EX DG Fisheye is also available in Canon EF , Nikon F (FX), Pentax KAF and Sigma SA mounts.
Focal Range
Sony FE 50mm F1.8 is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
75mm.
On the other hand, the Sigma 15mm F2.8 EX DG Fisheye is a prime lens with fixed focal lenght of 15mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 22.5mm.
