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 16mm F1.4 DC DN L 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 16mm F1.4 DC DN L with a length of 92mm, is 10mm shorter. Besides being longer, the Leica APO-SL 28mm F2 ASPH also has a larger diameter of 73mm compared to the Sigma 16mm F1.4 DC DN L's 72mm diameter.
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Below you can find a scaled side-by-side image of Leica APO-SL 28mm F2 ASPH and Sigma 16mm F1.4 DC DN L 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 16mm F1.4 DC DN L weighs 405g, 42% (295g) 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
Both the Leica APO-SL 28mm F2 ASPH and the Sigma 16mm F1.4 DC DN L have the same Filter thread size of 67mm.
Below are links to the 67mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Leica APO-SL 28mm F2 ASPH and the Sigma 16mm F1.4 DC DN L 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.
Focal Range
Leica APO-SL 28mm F2 ASPH is a prime lens with fixed focal lenght of 28mm.
On the other hand, the Sigma 16mm F1.4 DC DN L is a prime lens with fixed focal lenght of 16mm which has an effective (full-frame 35mm equivalent) focal range of 24mm when used on a APS-C / DX format camera.