The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony FE 20mm F1.8 G and the Leica Summilux-M 21mm f1.4 Asph 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. Sony FE 20mm F1.8 G is the longer of the two lenses at 85mm. The Leica Summilux-M 21mm f1.4 Asph with a length of 66mm, is 19mm shorter. Besides being longer, the Sony FE 20mm F1.8 G also has a larger diameter of 74mm compared to the Leica Summilux-M 21mm f1.4 Asph's 70mm 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 FE 20mm F1.8 G weighs 373g, which means it is 207g (35%) lighter than the Leica Summilux-M 21mm f1.4 Asph which has a weight of 580g.
Lens Mounts
The Sony FE 20mm F1.8 G has the Sony E lens mount whereas the Leica Summilux-M 21mm f1.4 Asph has the Leica M lens mount. Some of the latest released cameras that are compatible with these mounts are Sony A9 III, Sony A7C Mark II and Sony A7CR for the Sony E Mount and Leica M11 Monochrome, Leica M11 and Leica M10 for the Leica M Mount.
Focal Range
Sony FE 20mm F1.8 G 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 a 35mm (FF) equivalent of
30mm.
On the other hand, the Leica Summilux-M 21mm f1.4 Asph is a prime lens with fixed focal lenght of 21mm.