The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 56mm F1.4 DC DN C and the Leica Summilux-SL 50mm F1.4 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 Summilux-SL 50mm F1.4 ASPH is the longer of the two lenses at 124mm. The Sigma 56mm F1.4 DC DN C with a length of 60mm is 64mm shorter. Besides being longer, the Leica Summilux-SL 50mm F1.4 ASPH also has a larger diameter of 88mm compared to Sigma 56mm F1.4 DC DN C's 67mm 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 56mm F1.4 DC DN C weighs 280g, which means it is 785g (73%) lighter than the Leica Summilux-SL 50mm F1.4 ASPH which has a weight of 1065g.
Both Sigma 56mm F1.4 DC DN C has the Leica L lens mount whereas the Leica Summilux-SL 50mm F1.4 ASPH has the Leica SL lens mount. Some of the latest released cameras that are compatible with these mounts are Leica TL2, Leica TL and Leica T Typ 701 for the Leica L Mount and Sigma fp L, Leica SL2-S and Panasonic S5 for the Leica SL Mount.
Sigma 56mm F1.4 DC DN C is also available in Micro Four Thirds and Sony E mounts.
Sigma 56mm F1.4 DC DN C is a prime lens with fixed focal lenght of 56mm which has a 35mm equivalent focal range of 84mm when used on a APS-C / DX format camera. Leica Summilux-SL 50mm F1.4 ASPH is a prime lens with fixed focal lenght of 50mm.