The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 24mm F1.8 EX DG and the Rokinon 24mm f1.4 for their suitability to various photography scenarios:
Size and Weight Comparison
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 24mm F1.8 EX DG weighs 485g, which means it is 95g (16%) lighter than the Rokinon 24mm f1.4 which has a weight of 580g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Pentax KAF Mount for size comparison purposes.
Wideangle Lenses in Pentax KAF Mount for Size Comparison
Filter Threads
Both the Sigma 24mm F1.8 EX DG and the Rokinon 24mm f1.4 have the same Filter thread size of 77mm.
Below are links to the 77mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Sigma 24mm F1.8 EX DG and the Rokinon 24mm f1.4 has the same Pentax KAF lens mount. Some of the latest released cameras that are compatible with the Pentax KAF lenses are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III.
Sigma 24mm F1.8 EX DG is also available in Canon EF , Nikon F (FX), Four Thirds, Sony Alpha, Sigma SA, Canon EF, Pentax KAF, Sony Alpha, Sigma SA and Nikon F (FX) mounts.
Rokinon 24mm f1.4 is also available in Canon EF , Nikon F (FX), Four Thirds, Sony Alpha and Samsung NX mounts.
Focal Range
Both lenses have the same focal range of
24mm but while Sigma 24mm F1.8 EX DG has the fastest aperture of
F1.8, the Rokinon 24mm f1.4's widest aperture value is
F1.4.