The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica Super-Elmar-M 21mm f3.4 ASPH and the Leica Summarit-M 35mm f2.5 for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Leica Super-Elmar-M 21mm f3.4 ASPH is the longer of the two lenses at 43mm. The Leica Summarit-M 35mm f2.5 with a length of 34mm, is 9mm shorter. Besides being longer, the Leica Super-Elmar-M 21mm f3.4 ASPH also has a larger diameter of 53mm compared to the Leica Summarit-M 35mm f2.5's 51mm diameter.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Leica Summarit-M 35mm f2.5 weighs 220g, 21% (59g) lighter than the Leica Super-Elmar-M 21mm f3.4 ASPH's weight of 279g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Leica M Mount for size comparison purposes.
Wideangle Prime Lenses in Leica M Mount for Size Comparison
Lens Mounts
Both the Leica Super-Elmar-M 21mm f3.4 ASPH and the Leica Summarit-M 35mm f2.5 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 Super-Elmar-M 21mm f3.4 ASPH is a prime lens with fixed focal lenght of 21mm. Leica Summarit-M 35mm f2.5 is a prime lens with fixed focal lenght of 25-35mm.