The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang AF 18mm F2.8 FE and the Sigma 19mm F2.8 DN 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. Sigma 19mm F2.8 DN weighs 140g, 3% (5g) lighter than the Samyang AF 18mm F2.8 FE's weight of 145g.
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 18mm F2.8 FE and Sigma 19mm F2.8 DN 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.
Sigma 19mm F2.8 DN is also available in Micro Four Thirds mount.
Samyang AF 18mm F2.8 FE is a prime lens with fixed focal lenght of 18mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 27mm.
Sigma 19mm F2.8 DN is a prime lens with fixed focal lenght of 19mm which has a 35mm equivalent focal range of 27mm when used on a APS-C / DX format camera.