The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony E 20mm F2.8 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.Sigma 19mm F2.8 EX DN is the longer of the two lenses at 46mm. The Sony E 20mm F2.8 with a length of 20mm is 26mm shorter. On the other hand, the Sony E 20mm F2.8 has a larger diameter of 63mm 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. Sony E 20mm F2.8 weighs 69g, which means it is 71g (50%) lighter than the Sigma 19mm F2.8 EX DN which has a weight of 140g.
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 Sony E 20mm F2.8 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 FX30, Sony ZV-E10 and Sony A6600.
Sigma 19mm F2.8 EX DN is also available in Micro Four Thirds mount.
Sony E 20mm F2.8 is a prime lens with fixed focal lenght of 20mm which has an effective (full-frame 35mm equivalent) focal range of 30mm when used on a APS-C / DX format camera. 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.