The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Venus 25mm F2.8 2.5-5X Ultra Macro and the Samyang 24mm f1.4 for their suitability to various photography scenarios:
Size and Weight Comparison
Weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Venus 25mm F2.8 2.5-5X Ultra Macro weighs 400g, which means it is 180g (31%) lighter than the Samyang 24mm f1.4 which has a weight of 580g.
Lens Mounts
Both Venus 25mm F2.8 2.5-5X Ultra Macro has the Pentax KAF2 lens mount whereas the Samyang 24mm f1.4 has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF2 Mount and Pentax KF, Pentax K-3 III and Pentax K-1 II for the Pentax KAF Mount.
Venus 25mm F2.8 2.5-5X Ultra Macro is also available in Canon EF , Nikon F (DX) and Sony E 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
Venus 25mm F2.8 2.5-5X Ultra Macro is a prime lens with fixed focal lenght of 25mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 37.5mm.
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 an 35mm (FF) equivalent of 36mm.