The type of photography that you are planning to use is an important decision factor. Here we have evaluated the PENTAX15-30mm F2.8 ED WR 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. PENTAX15-30mm F2.8 ED WR is the longer of the two lenses at 144mm. The Sigma 15mm F2.8 EX DG Fisheye with a length of 65mm, is 79mm shorter. Besides being longer, the PENTAX15-30mm F2.8 ED WR also has a larger diameter of 99mm 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, 64% (670g) lighter than the PENTAX15-30mm F2.8 ED WR's weight of 1040g.
Lens Mounts
The PENTAX15-30mm F2.8 ED WR has the Pentax KAF3 lens mount whereas the Sigma 15mm F2.8 EX DG Fisheye has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF3 Mount and Pentax K-3 III Mono, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Sigma 15mm F2.8 EX DG Fisheye is also available in Canon EF , Nikon F (FX), Sony Alpha and Sigma SA mounts.
Focal Range
PENTAX15-30mm F2.8 ED WR has a focal range of 15-30mm and
2.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
22.5 - 45mm.
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.
