The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tokina Firin 20mm F2 FE MF and the Sigma 19mm F2.8 DN 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 19mm F2.8 DN weighs 140g, 71% (350g) lighter than the Tokina Firin 20mm F2 FE MF's weight of 490g.
Lens Mounts
Both the Tokina Firin 20mm F2 FE MF and the 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 A9 III, Sony A7C Mark II and Sony A7CR.
Tokina Firin 20mm F2 FE MF is also available in Sony E mount.
Sigma 19mm F2.8 DN is also available in Micro Four Thirds mount.
Focal Range
Tokina Firin 20mm F2 FE MF is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
30mm.
On the other hand, the Sigma 19mm F2.8 DN is a prime lens with fixed focal lenght of 19mm which has an effective (full-frame 35mm equivalent) focal range of 28.5mm when used on a APS-C / DX format camera.