The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sigma 20mm F1.4 DG DN A and the Leica APO 50mm f2 ASPH 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 20mm F1.4 DG DN A is the longer of the two lenses at 111mm. The Leica APO 50mm f2 ASPH with a length of 47mm, is 64mm shorter. Besides being longer, the Sigma 20mm F1.4 DG DN A also has a larger diameter of 88mm compared to the Leica APO 50mm f2 ASPH's 53mm 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. Leica APO 50mm f2 ASPH weighs 300g, 52% (335g) lighter than the Sigma 20mm F1.4 DG DN A's weight of 635g.
Filter Threads
The Sigma 20mm F1.4 DG DN A has a filter size of 82mm whereas the Leica APO 50mm f2 ASPH has a 39mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 82mm filters that we recommend you to consider for the Sigma 20mm F1.4 DG DN A:
And these are the 39mm filters that we recommend for the Leica APO 50mm f2 ASPH:
Lens Mounts
The Sigma 20mm F1.4 DG DN A has the Leica L lens mount whereas the Leica APO 50mm f2 ASPH has the Leica M lens mount. Some of the latest released cameras that are compatible with these mounts are Leica SL3-P, Panasonic S1 II and Panasonic S1 IIE for the Leica L Mount and Leica M EV1, Leica M11-D and Pixii Max for the Leica M Mount.
Sigma 20mm F1.4 DG DN A is also available in the Sony E mount.
Focal Range
Sigma 20mm F1.4 DG DN A is a prime lens with fixed focal lenght of 20mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
36mm.
On the other hand, the Leica APO 50mm f2 ASPH is a prime lens with fixed focal lenght of 50mm.
