The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Nikon 20mm f1.8G ED and the Sigma 10mm 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. Sigma 10mm F2.8 EX DC HSM Fisheye is the longer of the two lenses at 83mm. The Nikon 20mm f1.8G ED with a length of 81mm, is 2mm shorter. On the other hand, the Nikon 20mm f1.8G ED has a larger diameter of 83mm compared to the Sigma 10mm 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. Nikon 20mm f1.8G ED weighs 355g, which means it is 120g (25%) lighter than the Sigma 10mm F2.8 EX DC HSM Fisheye which has a weight of 475g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Nikon F (DX) Mount for size comparison purposes.
Ultra-Wideangle Lenses in Nikon F (DX) Mount for Size Comparison
Lens Mounts
Both the Nikon 20mm f1.8G ED and the Sigma 10mm F2.8 EX DC HSM Fisheye has the same Nikon F (DX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (DX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Sigma 10mm F2.8 EX DC HSM Fisheye is also available in Canon EF and Sigma SA mounts.
Focal Range
Nikon 20mm f1.8G ED 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 Sigma 10mm F2.8 EX DC HSM Fisheye is a prime lens with fixed focal lenght of 10mm which has an effective (full-frame 35mm equivalent) focal range of 15mm when used on a APS-C / DX format camera.
