The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tokina 10-17mm f3.5-4.5 Fisheye and the Sigma 15mm F2.8 EX DG 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. Tokina 10-17mm f3.5-4.5 Fisheye is the longer of the two lenses at 71mm. The Sigma 15mm F2.8 EX DG Fisheye with a length of 65mm, is 6mm shorter. On the other hand, the Sigma 15mm F2.8 EX DG Fisheye has a larger diameter of 74mm compared to the Tokina 10-17mm f3.5-4.5 Fisheye's 70mm 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. Tokina 10-17mm f3.5-4.5 Fisheye weighs 350g, which means it is 20g (5%) lighter than the Sigma 15mm F2.8 EX DG Fisheye which has a weight of 370g.
Lens Mounts
The Tokina 10-17mm f3.5-4.5 Fisheye has the Nikon F (DX) lens mount whereas the Sigma 15mm F2.8 EX DG Fisheye has the Sony Alpha lens mount. Some of the latest released cameras that are compatible with these mounts are Nikon D3500, Nikon D7500 and Nikon D5600 for the Nikon F (DX) Mount and Sony A99 II, Sony A68 and Sony A77 II for the Sony Alpha Mount.
Tokina 10-17mm f3.5-4.5 Fisheye is also available in the Canon EF mount.
Sigma 15mm F2.8 EX DG Fisheye is also available in Canon EF , Nikon F (FX), Pentax KAF and Sigma SA mounts.
Focal Range
Tokina 10-17mm f3.5-4.5 Fisheye has a focal range of 10-17mm and
1.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
15-25.5mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 15mm F2.8 EX DG Fisheye is a prime lens with fixed focal lenght of 15mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 22.5mm.
