The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 45mm F2.8 DG DN C and the Sigma 56mm F1.4 DC DN C 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 56mm F1.4 DC DN C is the longer of the two lenses at 60mm. The Sigma 45mm F2.8 DG DN C with a length of 46mm is 14mm shorter. Besides being longer, the Sigma 56mm F1.4 DC DN C also has a larger diameter of 67mm compared to Sigma 45mm F2.8 DG DN C's 64mm 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 45mm F2.8 DG DN C weighs 215g, which means it is 65g (23%) lighter than the Sigma 56mm F1.4 DC DN C which has a weight of 280g.
Below you can find the dimension and weight table of the 'Standard Prime Lenses in Leica L Mount for size comparison purposes.
Standard Prime Lenses in Leica L Mount for Size Comparison
Lens Mounts
Both Sigma 45mm F2.8 DG DN C and Sigma 56mm F1.4 DC DN C 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.
Sigma 45mm F2.8 DG DN C is also available in Sony E mount.
Sigma 56mm F1.4 DC DN C is also available in Micro Four Thirds and Sony E mounts.
Focal Range
Sigma 45mm F2.8 DG DN C is a prime lens with fixed focal lenght of 45mm. Sigma 56mm F1.4 DC DN C is a prime lens with fixed focal lenght of 56mm which has an effective (full-frame 35mm equivalent) focal range of 84mm when used on a APS-C / DX format camera.