The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica APO-SL 28mm F2 ASPH and the Sigma 24mm F3.5 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 APO-SL 28mm F2 ASPH is the longer of the two lenses at 102mm. The Sigma 24mm F3.5 DG DN C with a length of 49mm, is 53mm shorter. Besides being longer, the Leica APO-SL 28mm F2 ASPH also has a larger diameter of 73mm compared to the Sigma 24mm F3.5 DG DN C's 64mm diameter.
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Below you can find a scaled side-by-side image of Leica APO-SL 28mm F2 ASPH and Sigma 24mm F3.5 DG DN C to get a better idea of how their sizes compare in real life.
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 24mm F3.5 DG DN C weighs 225g, 67% (475g) lighter than the Leica APO-SL 28mm F2 ASPH's weight of 700g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Leica L Mount for size comparison purposes.
Wideangle Lenses in Leica L Mount for Size Comparison
Filter Threads
The Leica APO-SL 28mm F2 ASPH has a filter size of 67mm whereas the Sigma 24mm F3.5 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 APO-SL 28mm F2 ASPH:
And these are the 55mm filters that we recommend for the Sigma 24mm F3.5 DG DN C:
Lens Mounts
Both the Leica APO-SL 28mm F2 ASPH and the Sigma 24mm F3.5 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 24mm F3.5 DG DN C is also available in Sony E mount.
Focal Range
Leica APO-SL 28mm F2 ASPH is a prime lens with fixed focal lenght of 28mm.
On the other hand, the Sigma 24mm F3.5 DG DN C is a prime lens with fixed focal lenght of 24mm.