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 Panasonic Leica 25mm F1.4 for their suitability to various photography scenarios:
Size and Weight Comparison
The 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 Panasonic Leica 25mm F1.4 with a length of 55mm, is 5mm shorter. Besides being longer, the Sigma 56mm F1.4 DC DN C also has a larger diameter of 67mm compared to the Panasonic Leica 25mm F1.4's 63mm diameter.
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. Panasonic Leica 25mm F1.4 weighs 200g, 28% (80g) 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 Panasonic Leica 25mm F1.4 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.
Panasonic Leica 25mm F1.4 is also available in Four Thirds 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. Panasonic Leica 25mm F1.4 is a prime lens with fixed focal lenght of 25mm which has an effective (full-frame 35mm equivalent) focal range of 50mm when used on a FourThirds format camera.