The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 50mm F1.4 FE II and the Sigma 4.5mm F2.8 EX DC HSM 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. Samyang 50mm F1.4 FE II is the longer of the two lenses at 89mm. The Sigma 4.5mm F2.8 EX DC HSM Fisheye with a length of 78mm, is 11mm shorter. Besides being longer, the Samyang 50mm F1.4 FE II also has a larger diameter of 80mm compared to the Sigma 4.5mm F2.8 EX DC HSM Fisheye's 76mm 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 50mm F1.4 FE II weighs 420g, which means it is 50g (10%) lighter than the Sigma 4.5mm F2.8 EX DC HSM Fisheye which has a weight of 470g.
Lens Mounts
The Samyang 50mm F1.4 FE II has the Sony E lens mount whereas the Sigma 4.5mm F2.8 EX DC HSM Fisheye has the Nikon F (DX) 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 Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount.
Sigma 4.5mm F2.8 EX DC HSM Fisheye is also available in Canon EF and Sigma SA mounts.
Focal Range
Samyang 50mm F1.4 FE II 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 4.5mm F2.8 EX DC HSM Fisheye is a prime lens with fixed focal lenght of 5mm which has an effective (full-frame 35mm equivalent) focal range of 7.5mm when used on a APS-C / DX format camera.
