The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony E 15mm F1.4 G and the ZEISS Loxia 21mm F2.8 for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. ZEISS Loxia 21mm F2.8 is the longer of the two lenses at 72mm. The Sony E 15mm F1.4 G with a length of 70mm, is 2mm shorter. On the other hand, the Sony E 15mm F1.4 G has a larger diameter of 67mm compared to the ZEISS Loxia 21mm F2.8's 62mm diameter.
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. Sony E 15mm F1.4 G weighs 219g, which means it is 175g (44%) lighter than the ZEISS Loxia 21mm F2.8 which has a 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 Lenses in Sony E Mount for Size Comparison
Filter Threads
The Sony E 15mm F1.4 G has a filter size of 55mm whereas the ZEISS Loxia 21mm F2.8 has a 52mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 55mm filters that we recommend you to consider for the Sony E 15mm F1.4 G:
And these are the 52mm filters that we recommend for the ZEISS Loxia 21mm F2.8:
Lens Mounts
Both the Sony E 15mm F1.4 G and the ZEISS Loxia 21mm F2.8 has the same Sony E lens mount. Some of the latest released cameras that are compatible with the Sony E lenses are Sony ZV-E10 II, Sony A6700 and Sony FX30.
Focal Range
Sony E 15mm F1.4 G is a prime lens with fixed focal lenght of 15mm which has an effective (full-frame 35mm equivalent) focal range of
22.5mm when used on a APS-C / DX format camera.
On the other hand, the 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.