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 DN 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.Leica APO-Summicron-SL 75mm F2 ASPH is the longer of the two lenses at 102mm. The Sigma 85mm F1.4 DG DN A with a length of 94mm is 8mm shorter. On the other hand, the Sigma 85mm F1.4 DG DN A has a larger diameter of 83mm 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. Sigma 85mm F1.4 DG DN A weighs 630g, which means it is 90g (12%) lighter than the Leica APO-Summicron-SL 75mm F2 ASPH which has a weight of 720g.
Lens Mounts
Both Sigma 85mm F1.4 DG DN A and Leica APO-Summicron-SL 75mm 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
Sigma 85mm F1.4 DG DN 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.