The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang AF 24mm F2.8 FE and the ZEISS Loxia 21mm F2.8 for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.ZEISS Loxia 21mm F2.8 is the longer of the two lenses at 72mm. The Samyang AF 24mm F2.8 FE with a length of 37mm is 35mm shorter. Besides being longer, the ZEISS Loxia 21mm F2.8 also has a larger diameter of 62mm compared to Samyang AF 24mm F2.8 FE's 61mm diameter.
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. Samyang AF 24mm F2.8 FE weighs 93g, which means it is 301g (76%) lighter than the ZEISS Loxia 21mm F2.8 which has a weight of 394g.
Below you can find the dimension and weight table of the 'Wideangle Prime Lenses in Sony E Mount for size comparison purposes.
Wideangle Prime Lenses in Sony E Mount for Size Comparison
Both Samyang AF 24mm F2.8 FE and ZEISS Loxia 21mm F2.8 has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony A7R V, Sony FX30 and Sony A7 IV.
Samyang AF 24mm F2.8 FE 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.
ZEISS Loxia 21mm F2.8 is a prime lens with fixed focal lenght of 21mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 31.5mm.