The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica Thambar-M 90mm F2.2 and the Leica Summarit-M 75mm 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 Thambar-M 90mm F2.2 is the longer of the two lenses at 90mm. The Leica Summarit-M 75mm f2.5 with a length of 61mm, is 29mm shorter. Besides being longer, the Leica Thambar-M 90mm F2.2 also has a larger diameter of 57mm compared to the Leica Summarit-M 75mm f2.5's 55mm 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 75mm f2.5 weighs 345g, 31% (155g) lighter than the Leica Thambar-M 90mm F2.2's weight of 500g.
Below you can find the dimension and weight table of the Telephoto Prime Lenses in Leica M Mount for size comparison purposes.
Telephoto Prime Lenses in Leica M Mount for Size Comparison
Lens Mounts
Both the Leica Thambar-M 90mm F2.2 and the Leica Summarit-M 75mm 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, Leica M10 and Leica M Typ 262.
Focal Range
Leica Thambar-M 90mm F2.2 is a prime lens with fixed focal lenght of 90mm. Leica Summarit-M 75mm f2.5 is a prime lens with fixed focal lenght of 75mm.