The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 12mm f1.4 and the Rokinon 8mm f2.8 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. Rokinon 8mm f2.8 Fisheye is the longer of the two lenses at 77mm. The Sigma 12mm f1.4 with a length of 70mm, is 7mm shorter. Besides being longer, the Rokinon 8mm f2.8 Fisheye also has a larger diameter of 75mm compared to the Sigma 12mm f1.4's 68mm 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 12mm f1.4 weighs 235g, which means it is 208g (46%) lighter than the Rokinon 8mm f2.8 Fisheye which has a weight of 443g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Fujifilm X Mount for size comparison purposes.
Ultra-Wideangle Lenses in Fujifilm X Mount for Size Comparison
Lens Mounts
Both the Sigma 12mm f1.4 and the Rokinon 8mm f2.8 Fisheye has the same Fujifilm X lens mount. Some of the latest released cameras that are compatible with the Fujifilm X lenses are Fujifilm X-T30 III, Fujifilm X-E5 and Fujifilm X-M5.
Sigma 12mm f1.4 is also available in the Sony E and Canon RF mounts.
Focal Range
Sigma 12mm f1.4 is a prime lens with fixed focal lenght of 12mm which has an effective (full-frame 35mm equivalent) focal range of
18mm when used on a APS-C / DX format camera.
On the other hand, the Rokinon 8mm f2.8 Fisheye is a prime lens with fixed focal lenght of 8mm which has an effective (full-frame 35mm equivalent) focal range of 12mm when used on a APS-C / DX format camera.
