The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica Summarit-M 90mm F2.4 ASPH 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 Summarit-M 90mm F2.4 ASPH is the longer of the two lenses at 67mm. The Leica Summarit-M 75mm f2.5 with a length of 61mm, is 6mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 55mm.
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, 4% (15g) lighter than the Leica Summarit-M 90mm F2.4 ASPH's weight of 360g.
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
Both the Leica Summarit-M 90mm F2.4 ASPH 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 Monochrome, Leica M11 and Leica M10.
Leica Summarit-M 90mm F2.4 ASPH 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.