The type of photography that you are planning to use is an important decision factor. Here we have evaluated the ZEISS Loxia 21mm F2.8 and the Sony FE 35mm F2.8 ZA CZ for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. ZEISS Loxia 21mm F2.8 is the longer of the two lenses at 72mm. The Sony FE 35mm F2.8 ZA CZ with a length of 37mm, is 35mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 62mm.
The 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 FE 35mm F2.8 ZA CZ weighs 120g, 69% (274g) lighter than the ZEISS Loxia 21mm F2.8's weight of 394g.
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 the ZEISS Loxia 21mm F2.8 and the Sony FE 35mm F2.8 ZA CZ has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony ZV-E1, Sony A7R V and Sony FX30.
ZEISS Loxia 21mm F2.8 is a prime lens with fixed focal lenght of 21mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 31.5mm.
Sony FE 35mm F2.8 ZA CZ 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 a 35mm (FF) equivalent of 52.5mm.