The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Voigtlander 21mm F1.8 Ultron and the Carl Zeiss Distagon T4/18 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. Voigtlander 21mm F1.8 Ultron is the longer of the two lenses at 92mm. The Carl Zeiss Distagon T4/18 ZM with a length of 71mm, is 21mm shorter. On the other hand, the Carl Zeiss Distagon T4/18 ZM has a larger diameter of 65mm compared to the Voigtlander 21mm F1.8 Ultron'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. Carl Zeiss Distagon T4/18 ZM weighs 350g, 15% (62g) lighter than the Voigtlander 21mm F1.8 Ultron's weight of 412g.
Filter Threads
Both the Voigtlander 21mm F1.8 Ultron and the Carl Zeiss Distagon T4/18 ZM have the same Filter thread size of 58mm.
Below are links to the 58mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Voigtlander 21mm F1.8 Ultron and the Carl Zeiss Distagon T4/18 ZM has the same Leica M lens mount. Some of the latest released cameras that are compatible with the Leica M lenses are Leica M11 Monochrome, Leica M11 and Leica M10.
Focal Range
Voigtlander 21mm F1.8 Ultron is a prime lens with fixed focal lenght of 21mm.
On the other hand, the Carl Zeiss Distagon T4/18 ZM is a prime lens with fixed focal lenght of 18mm.