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 42.5mm F1.7 OIS for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Sigma 56mm F1.4 DC DN C is the longer of the two lenses at 60mm. The Panasonic 42.5mm F1.7 OIS with a length of 50mm, is 10mm shorter. Besides being longer, the Sigma 56mm F1.4 DC DN C also has a larger diameter of 67mm compared to the Panasonic 42.5mm F1.7 OIS's 55mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Panasonic 42.5mm F1.7 OIS weighs 130g, 53% (150g) 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 Lenses in Micro Four Thirds Mount for Size Comparison
Filter Threads
The Sigma 56mm F1.4 DC DN C has a filter size of 55mm whereas the Panasonic 42.5mm F1.7 OIS has a 37mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 55mm filters that we recommend you to consider for the Sigma 56mm F1.4 DC DN C:
And these are the 37mm filters that we recommend for the Panasonic 42.5mm F1.7 OIS:
Lens Mounts
Both the Sigma 56mm F1.4 DC DN C and the Panasonic 42.5mm F1.7 OIS 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-1 II, Panasonic G9 II and OM System OM-5.
Sigma 56mm F1.4 DC DN C is also available in Sony E and Leica L mounts.
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.
On the other hand, the Panasonic 42.5mm F1.7 OIS is a prime lens with fixed focal lenght of 43mm which has an effective (full-frame 35mm equivalent) focal range of 86mm when used on a FourThirds format camera.