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 Sigma 30mm F2.8 DN for their suitability to various photography scenarios:
Size and Weight Comparison
The 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 30mm F2.8 DN weighs 135g, 51% (145g) lighter than the Sigma 56mm F1.4 DC DN C's weight of 280g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Micro Four Thirds Mount for size comparison purposes.
Standard Prime Lenses in Micro Four Thirds Mount for Size Comparison
Lens Mounts
Both the Sigma 56mm F1.4 DC DN C and the Sigma 30mm F2.8 DN has the same Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with the Micro Four Thirds lenses are OM System OM-5, Panasonic GH6 and OM System OM-1.
Sigma 56mm F1.4 DC DN C is also available in Sony E and Leica L mounts.
Sigma 30mm F2.8 DN is also available in Sony E mount.
Focal Range
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 112mm when used on a APS-C / DX format camera. Sigma 30mm F2.8 DN is a prime lens with fixed focal lenght of 30mm which has an effective (full-frame 35mm equivalent) focal range of 45mm when used on a APS-C / DX format camera.