The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 85mm F1.4 DG HSM A and the Leica APO-Summicron-SL 75mm F2 ASPH for their suitability to various photography scenarios:
Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Sigma 85mm F1.4 DG HSM A is the longer of the two lenses at 126mm. The Leica APO-Summicron-SL 75mm F2 ASPH with a length of 102mm is 24mm shorter. Besides being longer, the Sigma 85mm F1.4 DG HSM A also has a larger diameter of 95mm compared to Leica APO-Summicron-SL 75mm F2 ASPH's 73mm diameter.
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 75mm F2 ASPH weighs 720g, 36% (410g) lighter than the Sigma 85mm F1.4 DG HSM A's weight of 1130g.
Lens Mounts
Both Sigma 85mm F1.4 DG HSM A has the Leica L lens mount whereas the Leica APO-Summicron-SL 75mm F2 ASPH has the Leica SL lens mount. Some of the latest released cameras that are compatible with these mounts are Sigma fp L, Leica SL2-S and Panasonic S5 for the Leica L Mount and Sigma fp L, Leica SL2-S and Panasonic S5 for the Leica SL Mount.
Focal Range
Sigma 85mm F1.4 DG HSM A is a prime lens with fixed focal lenght of 85mm. Leica APO-Summicron-SL 75mm F2 ASPH is a prime lens with fixed focal lenght of 75mm.