The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 30mm F1.4 EX DC HSM and the Samyang 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 30mm F1.4 EX DC HSM weighs 430g, which means it is 150g (25%) lighter than the Samyang 24mm f1.4 which has a weight of 580g.
Filter Threads
The Sigma 30mm F1.4 EX DC HSM has a filter size of 62mm whereas the Samyang 24mm f1.4 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 62mm filters that we recommend you to consider for the Sigma 30mm F1.4 EX DC HSM:
And these are the 77mm filters that we recommend for the Samyang 24mm f1.4:
Lens Mounts
Both the Sigma 30mm F1.4 EX DC HSM and the Samyang 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 30mm F1.4 EX DC HSM is also available in Canon EF-S , Nikon F (DX), Four Thirds, Sony Alpha and Sigma SA mounts.
Samyang 24mm f1.4 is also available in Canon EF , Nikon F (FX), Four Thirds, Sony Alpha, Sony E and Samsung NX mounts.
Focal Range
Sigma 30mm F1.4 EX DC HSM is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of
45mm when used on a APS-C / DX format camera.
On the other hand, the Samyang 24mm f1.4 is a prime lens with fixed focal lenght of 24mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 36mm.