The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica Summarit-M 35mm f2.5 and the Leica Elmarit-M 21mm f2.8 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. Leica Elmarit-M 21mm f2.8 ASPH is the longer of the two lenses at 46mm. The Leica Summarit-M 35mm f2.5 with a length of 34mm, is 12mm shorter. Besides being longer, the Leica Elmarit-M 21mm f2.8 ASPH also has a larger diameter of 58mm compared to the Leica Summarit-M 35mm f2.5's 51mm 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. Leica Summarit-M 35mm f2.5 weighs 220g, which means it is 80g (26%) lighter than the Leica Elmarit-M 21mm f2.8 ASPH which has a weight of 300g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Leica M Mount for size comparison purposes.
Wideangle Lenses in Leica M Mount for Size Comparison
Filter Threads
The Leica Summarit-M 35mm f2.5 has a filter size of 39mm whereas the Leica Elmarit-M 21mm f2.8 ASPH has a 55mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 39mm filters that we recommend you to consider for the Leica Summarit-M 35mm f2.5:
And these are the 55mm filters that we recommend for the Leica Elmarit-M 21mm f2.8 ASPH:
Lens Mounts
Both the Leica Summarit-M 35mm f2.5 and the Leica Elmarit-M 21mm f2.8 ASPH 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 Summarit-M 35mm f2.5 is a prime lens with fixed focal lenght of 25-35mm.
On the other hand, the Leica Elmarit-M 21mm f2.8 ASPH is a prime lens with fixed focal lenght of 21mm.