The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tokina 16-28mm f2.8 Pro FX 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 16-28mm f2.8 Pro FX is the longer of the two lenses at 133mm. The Sigma 15mm F2.8 EX DG Fisheye with a length of 65mm, is 68mm shorter. Besides being longer, the Tokina 16-28mm f2.8 Pro FX also has a larger diameter of 90mm compared to the Sigma 15mm F2.8 EX DG Fisheye's 74mm 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 15mm F2.8 EX DG Fisheye weighs 370g, 61% (580g) lighter than the Tokina 16-28mm f2.8 Pro FX's weight of 950g.
Lens Mounts
Both the Tokina 16-28mm f2.8 Pro FX and the Sigma 15mm F2.8 EX DG Fisheye has the same Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (FX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Tokina 16-28mm f2.8 Pro FX is also available in the Canon EF mount.
Sigma 15mm F2.8 EX DG Fisheye is also available in Canon EF , Pentax KAF, Sony Alpha and Sigma SA mounts.
Focal Range
Tokina 16-28mm f2.8 Pro FX has a focal range of 16-28mm and
1.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
24 - 42mm.
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.
