The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica Summilux-M 90mm F1.5 ASPH and the Voigtlander 75mm F1.8 Heliar Classic 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. Leica Summilux-M 90mm F1.5 ASPH is the longer of the two lenses at 91mm. The Voigtlander 75mm F1.8 Heliar Classic with a length of 74mm, is 17mm shorter. Besides being longer, the Leica Summilux-M 90mm F1.5 ASPH also has a larger diameter of 74mm compared to the Voigtlander 75mm F1.8 Heliar Classic's 58mm 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 75mm F1.8 Heliar Classic weighs 427g, 57% (583g) lighter than the Leica Summilux-M 90mm F1.5 ASPH's weight of 1010g.
Below you can find the dimension and weight table of the Telephoto Prime Lenses in Leica M Mount for size comparison purposes.
Telephoto Lenses in Leica M Mount for Size Comparison
Lens Mounts
Both the Leica Summilux-M 90mm F1.5 ASPH and the Voigtlander 75mm F1.8 Heliar Classic 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
Leica Summilux-M 90mm F1.5 ASPH is a prime lens with fixed focal lenght of 90mm.
On the other hand, the Voigtlander 75mm F1.8 Heliar Classic is a prime lens with fixed focal lenght of 75mm.