The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 10mm f2.8 and the Rokinon 8mm f2.8 Fisheye for their suitability to various photography scenarios:
Size and Weight Comparison
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. Rokinon 8mm f2.8 Fisheye weighs 443g, 23% (137g) lighter than the Samyang 10mm f2.8's weight of 580g.
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 Samyang 10mm f2.8 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-S20, Fujifilm X-T5 and Fujifilm X-H2.
Samyang 10mm f2.8 is also available in Canon EF , Canon EF-M, Nikon F (DX), Four Thirds and Micro Four Thirds mounts.
Focal Range
Samyang 10mm f2.8 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.
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.