The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica APO-Summicron-SL 75mm F2 ASPH and the Leica APO-Summicron-SL 90mm F2 ASPH for their suitability to various photography scenarios:
Size and Weight Comparison
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 APO-Summicron-SL 90mm F2 ASPH weighs 700g, 2% (20g) lighter than the Leica APO-Summicron-SL 75mm F2 ASPH's weight of 720g.
Lens Mounts
Both Leica APO-Summicron-SL 75mm F2 ASPH and Leica APO-Summicron-SL 90mm F2 ASPH has the same Leica L lens mount. Some of the latest released cameras that are compatible with the Leica L lenses are Panasonic S5 II, Panasonic S5 II X and Sigma fp L.
Focal Range
Leica APO-Summicron-SL 75mm F2 ASPH is a prime lens with fixed focal lenght of 75mm. Leica APO-Summicron-SL 90mm F2 ASPH is a prime lens with fixed focal lenght of 90mm.