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 Voigtlander 15mm F4.5 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 Voigtlander 15mm F4.5 with a length of 38mm, is 54mm shorter. Besides being longer, the Voigtlander 21mm F1.8 Ultron also has a larger diameter of 62mm compared to the Voigtlander 15mm F4.5's 59mm 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. Voigtlander 15mm F4.5 weighs 156g, 62% (256g) lighter than the Voigtlander 21mm F1.8 Ultron's weight of 412g.
Filter Threads
The Voigtlander 21mm F1.8 Ultron has a filter size of 58mm whereas the Voigtlander 15mm F4.5 has a 52mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 58mm filters that we recommend you to consider for the Voigtlander 21mm F1.8 Ultron:
And these are the 52mm filters that we recommend for the Voigtlander 15mm F4.5:
Lens Mounts
Both the Voigtlander 21mm F1.8 Ultron and the Voigtlander 15mm F4.5 has the same Leica M lens mount. Some of the latest released cameras that are compatible with the Leica M lenses are Leica M EV1, Leica M11-D and Pixii Max.
Focal Range
Voigtlander 21mm F1.8 Ultron is a prime lens with fixed focal lenght of 21mm.
On the other hand, the Voigtlander 15mm F4.5 is a prime lens with fixed focal lenght of 15mm.
