The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Nikon AF-P DX 10-20mm F4.5-5.6G VR 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. Nikon AF-P DX 10-20mm F4.5-5.6G VR is the longer of the two lenses at 73mm. The Sigma 15mm F2.8 EX DG Fisheye with a length of 65mm, is 8mm shorter. Besides being longer, the Nikon AF-P DX 10-20mm F4.5-5.6G VR also has a larger diameter of 77mm 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. Nikon AF-P DX 10-20mm F4.5-5.6G VR weighs 230g, which means it is 140g (37%) lighter than the Sigma 15mm F2.8 EX DG Fisheye which has a weight of 370g.
Lens Mounts
The Nikon AF-P DX 10-20mm F4.5-5.6G VR has the Nikon F (DX) lens mount whereas the Sigma 15mm F2.8 EX DG Fisheye has the Nikon F (FX) 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 Nikon D6, Nikon D780 and Nikon D3500 for the Nikon F (FX) Mount.
Sigma 15mm F2.8 EX DG Fisheye is also available in Canon EF , Pentax KAF, Sony Alpha and Sigma SA mounts.
Focal Range
Nikon AF-P DX 10-20mm F4.5-5.6G VR 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.
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.
