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 Carl Zeiss C Biogon T4,5/21 ZM 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 Carl Zeiss C Biogon T4,5/21 ZM with a length of 56mm, is 29mm shorter. Besides being longer, the Sony FE 20mm F1.8 G also has a larger diameter of 74mm compared to the Carl Zeiss C Biogon T4,5/21 ZM's 53mm 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. Carl Zeiss C Biogon T4,5/21 ZM weighs 210g, 43% (163g) lighter than the Sony FE 20mm F1.8 G's weight of 373g.
Filter Threads
The Sony FE 20mm F1.8 G has a filter size of 67mm whereas the Carl Zeiss C Biogon T4,5/21 ZM has a 46mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Sony FE 20mm F1.8 G:
And these are the 46mm filters that we recommend for the Carl Zeiss C Biogon T4,5/21 ZM:
Lens Mounts
The Sony FE 20mm F1.8 G has the Sony E lens mount whereas the Carl Zeiss C Biogon T4,5/21 ZM has the Leica M lens mount. Some of the latest released cameras that are compatible with these mounts are Sony FX5, Sony A7R VI and Sony A7 V for the Sony E Mount and Leica M EV1, Leica M11-D and Pixii Max 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 Carl Zeiss C Biogon T4,5/21 ZM is a prime lens with fixed focal lenght of 21mm.
