The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 20mm F1.8 EX DG RF and the Samsung D-Xenon 12-24mm F4 ED 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 20mm F1.8 EX DG RF is the longer of the two lenses at 90mm. The Samsung D-Xenon 12-24mm F4 ED with a length of 88mm, is 2mm shorter. Besides being longer, the Sigma 20mm F1.8 EX DG RF also has a larger diameter of 89mm compared to the Samsung D-Xenon 12-24mm F4 ED's 84mm 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. Samsung D-Xenon 12-24mm F4 ED weighs 430g, 17% (90g) lighter than the Sigma 20mm F1.8 EX DG RF's weight of 520g.
Filter Threads
The Sigma 20mm F1.8 EX DG RF has a filter size of 82mm whereas the Samsung D-Xenon 12-24mm F4 ED has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 82mm filters that we recommend you to consider for the Sigma 20mm F1.8 EX DG RF:
And these are the 77mm filters that we recommend for the Samsung D-Xenon 12-24mm F4 ED:
Lens Mounts
The Sigma 20mm F1.8 EX DG RF has the Pentax KAF lens mount whereas the Samsung D-Xenon 12-24mm F4 ED has the Pentax KAF2 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 KAF Mount and , and for the Pentax KAF2 Mount.
Sigma 20mm F1.8 EX DG RF is also available in the Canon EF , Nikon F (DX), Sony Alpha and Sigma SA mounts.
Focal Range
Sigma 20mm F1.8 EX DG RF is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
30mm.
On the other hand, the Samsung D-Xenon 12-24mm F4 ED has a focal range of 12-24mm and 2.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 18-36mm when used on a APS-C / DX format camera.
