The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 21mm F1.4 ED AS UMC CS 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. Voigtlander Nokton 17.5mm F0.95 ASPH is the longer of the two lenses at 80mm. The Samyang 21mm F1.4 ED AS UMC CS with a length of 68mm, is 12mm shorter. On the other hand, the Samyang 21mm F1.4 ED AS UMC CS has a larger diameter of 64mm 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. Samyang 21mm F1.4 ED AS UMC CS weighs 275g, which means it is 265g (49%) lighter than the Voigtlander Nokton 17.5mm F0.95 ASPH which has a weight of 540g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Micro Four Thirds Mount for size comparison purposes.
Wideangle Lenses in Micro Four Thirds Mount for Size Comparison
Filter Threads
Both the Samyang 21mm F1.4 ED AS UMC CS and the Voigtlander Nokton 17.5mm F0.95 ASPH 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 Samyang 21mm F1.4 ED AS UMC CS and the Voigtlander Nokton 17.5mm F0.95 ASPH has the same Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with the Micro Four Thirds lenses are OM System OM-1 II, Panasonic G9 II and OM System OM-5.
Samyang 21mm F1.4 ED AS UMC CS is also available in Canon EF-M , Fujifilm X and Sony E mounts.
Focal Range
Samyang 21mm F1.4 ED AS UMC CS is a prime lens with fixed focal lenght of 21mm which has an effective (full-frame 35mm equivalent) focal range of
42mm when used on a APS-C / DX format camera.
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.