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 EX DN for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Tokina Firin 20mm F2 FE MF is the longer of the two lenses at 69mm. The Sigma 19mm F2.8 EX DN with a length of 46mm is 23mm shorter. Besides being longer, the Tokina Firin 20mm F2 FE MF also has a larger diameter of 62mm compared to Sigma 19mm F2.8 EX DN'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. Sigma 19mm F2.8 EX DN weighs 140g, 71% (350g) lighter than the Tokina Firin 20mm F2 FE MF's weight of 490g.
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
Lens Mounts
Both Tokina Firin 20mm F2 FE MF and Sigma 19mm F2.8 EX 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.
Tokina Firin 20mm F2 FE MF is also available in Sony E mount.
Sigma 19mm F2.8 EX 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 an 35mm (FF) equivalent of 30mm.
Sigma 19mm F2.8 EX 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.