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 Distagon T3,5/18 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 Distagon T3,5/18 with a length of 84mm, is 1mm shorter. On the other hand, the Carl Zeiss Distagon T3,5/18 has a larger diameter of 87mm compared to the Sony FE 20mm F1.8 G's 74mm 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 97g (20%) lighter than the Carl Zeiss Distagon T3,5/18 which has a weight of 470g.
Filter Threads
The Sony FE 20mm F1.8 G has a filter size of 67mm whereas the Carl Zeiss Distagon T3,5/18 has a 82mm 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 82mm filters that we recommend for the Carl Zeiss Distagon T3,5/18:
Lens Mounts
The Sony FE 20mm F1.8 G has the Sony E lens mount whereas the Carl Zeiss Distagon T3,5/18 has the Pentax KAF 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 Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Carl Zeiss Distagon T3,5/18 is also available in Canon EF and Nikon F (FX) mounts.
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 Distagon T3,5/18 is a prime lens with fixed focal lenght of 18mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 27mm.