The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 10mm F2.8 EX DC HSM Fisheye and the Samyang 8mm F3.5 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 Samyang 8mm F3.5 Fisheye with a length of 77mm, is 6mm shorter. Besides being longer, the Sigma 10mm F2.8 EX DC HSM Fisheye also has a larger diameter of 76mm compared to the Samyang 8mm F3.5 Fisheye's 75mm 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 8mm F3.5 Fisheye weighs 443g, 6% (32g) lighter than the Sigma 10mm F2.8 EX DC HSM Fisheye's weight of 475g.
Below you can find the dimension and weight table of the Wideangle Fisheye Prime Lenses in Canon EF Mount for size comparison purposes.
Ultra-Wideangle Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Sigma 10mm F2.8 EX DC HSM Fisheye and the Samyang 8mm F3.5 Fisheye has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon T8i, Canon 90D and Canon SL3.
Sigma 10mm F2.8 EX DC HSM Fisheye is also available in Sigma SA and Nikon F (DX) mounts.
Samyang 8mm F3.5 Fisheye is also available in Nikon F (DX) , Four Thirds, Pentax KAF, Sony Alpha and Samsung NX mounts.
Focal Range
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
16mm when used on a APS-C / DX format camera.
On the other hand, the Samyang 8mm F3.5 Fisheye is a prime lens with fixed focal lenght of 8mm which has an effective (full-frame 35mm equivalent) focal range of 12.8mm when used on a APS-C / DX format camera.