The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony Distagon T FE 35mm F1.4 ZA and the Sigma 30mm 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 30mm F2.8 DN weighs 135g, 78% (495g) lighter than the Sony Distagon T FE 35mm F1.4 ZA's weight of 630g.
Both Sony Distagon T FE 35mm F1.4 ZA and Sigma 30mm 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 30mm F2.8 DN is also available in Micro Four Thirds mount.
Sony Distagon T FE 35mm F1.4 ZA is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 52.5mm.
Sigma 30mm F2.8 DN is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of 45mm when used on a APS-C / DX format camera.