The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica Elmarit-M 21mm f2.8 ASPH and the Carl Zeiss C Biogon T4,5/21 ZM 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. Carl Zeiss C Biogon T4,5/21 ZM is the longer of the two lenses at 56mm. The Leica Elmarit-M 21mm f2.8 ASPH with a length of 46mm, is 10mm shorter. On the other hand, the Leica Elmarit-M 21mm f2.8 ASPH has a larger diameter of 58mm compared to the Carl Zeiss C Biogon T4,5/21 ZM's 53mm 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. Carl Zeiss C Biogon T4,5/21 ZM weighs 210g, 30% (90g) lighter than the Leica Elmarit-M 21mm f2.8 ASPH's 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 Elmarit-M 21mm f2.8 ASPH has a filter size of 55mm whereas the Carl Zeiss C Biogon T4,5/21 ZM has a 46mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 55mm filters that we recommend you to consider for the Leica Elmarit-M 21mm f2.8 ASPH:
And these are the 46mm filters that we recommend for the Carl Zeiss C Biogon T4,5/21 ZM:
Lens Mounts
Both the Leica Elmarit-M 21mm f2.8 ASPH and the Carl Zeiss C Biogon T4,5/21 ZM 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
Both lenses have the same focal range of
21mm but while Leica Elmarit-M 21mm f2.8 ASPH has the fastest aperture of
F2.8, the Carl Zeiss C Biogon T4,5/21 ZM's widest aperture value is
F4.5.