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 Voigtlander Nokton 17.5mm F0.95 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 Voigtlander Nokton 17.5mm F0.95 ASPH with a length of 80mm, is 5mm shorter. Besides being longer, the Sony FE 20mm F1.8 G also has a larger diameter of 74mm compared to the Voigtlander Nokton 17.5mm F0.95 ASPH's 63mm 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 167g (30%) lighter than the Voigtlander Nokton 17.5mm F0.95 ASPH which has a weight of 540g.
Filter Threads
The Sony FE 20mm F1.8 G has a filter size of 67mm whereas the Voigtlander Nokton 17.5mm F0.95 ASPH has a 58mm 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 58mm filters that we recommend for the Voigtlander Nokton 17.5mm F0.95 ASPH:
Lens Mounts
The Sony FE 20mm F1.8 G has the Sony E lens mount whereas the Voigtlander Nokton 17.5mm F0.95 ASPH has the Micro Four Thirds 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 OM System OM-1 II, Panasonic G9 II and OM System OM-5 for the Micro Four Thirds 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 Voigtlander Nokton 17.5mm F0.95 ASPH is a prime lens with fixed focal lenght of 18mm which has an effective (full-frame 35mm equivalent) focal range of 36mm when used on a FourThirds format camera.