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 10-20mm F3.5 EX DC HSM 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 10-20mm F3.5 EX DC HSM is the longer of the two lenses at 88mm. The Tokina 10-17mm f3.5-4.5 Fisheye with a length of 71mm, is 17mm shorter. Besides being longer, the Sigma 10-20mm F3.5 EX DC HSM also has a larger diameter of 87mm 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 170g (32%) lighter than the Sigma 10-20mm F3.5 EX DC HSM which has a weight of 520g.
Below you can find the dimension and weight table of the Wideangle Zoom 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 Tokina 10-17mm f3.5-4.5 Fisheye and the Sigma 10-20mm F3.5 EX DC HSM 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 D3500, Nikon D7500 and Nikon D5600.
Tokina 10-17mm f3.5-4.5 Fisheye is also available in Canon EF mount.
Sigma 10-20mm F3.5 EX DC HSM is also available in Canon EF , Pentax KAF3, Sony Alpha 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 10-20mm F3.5 EX DC HSM has a focal range of 10-20mm and 2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 15-30mm when used on a APS-C / DX format camera.