The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica SL 35mm f2 ASPH and the Sigma 45mm F2.8 DG DN C 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. Leica SL 35mm f2 ASPH is the longer of the two lenses at 83mm. The Sigma 45mm F2.8 DG DN C with a length of 46mm, is 37mm shorter. Besides being longer, the Leica SL 35mm f2 ASPH also has a larger diameter of 75mm compared to the Sigma 45mm F2.8 DG DN C's 64mm 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. Sigma 45mm F2.8 DG DN C weighs 215g, 46% (185g) lighter than the Leica SL 35mm f2 ASPH's weight of 400g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Leica L Mount for size comparison purposes.
Standard Lenses in Leica L Mount for Size Comparison
Filter Threads
The Leica SL 35mm f2 ASPH has a filter size of 67mm whereas the Sigma 45mm F2.8 DG DN C has a 55mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Leica SL 35mm f2 ASPH:
And these are the 55mm filters that we recommend for the Sigma 45mm F2.8 DG DN C:
Lens Mounts
Both the Leica SL 35mm f2 ASPH and the Sigma 45mm F2.8 DG DN C has the same Leica L lens mount. Some of the latest released cameras that are compatible with the Leica L lenses are Leica SL3, Panasonic S5 II and Panasonic S5 II X.
Sigma 45mm F2.8 DG DN C is also available in Sony E mount.
Focal Range
Leica SL 35mm f2 ASPH is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
52.5mm.
On the other hand, the Sigma 45mm F2.8 DG DN C is a prime lens with fixed focal lenght of 45mm.