The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Laowa 17mm f4 TS and the Sigma 20mm F2 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. Laowa 17mm f4 TS is the longer of the two lenses at 111mm. The Sigma 20mm F2 DG DN C with a length of 72mm, is 39mm shorter. Besides being longer, the Laowa 17mm f4 TS also has a larger diameter of 93mm compared to the Sigma 20mm F2 DG DN C's 70mm 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 20mm F2 DG DN C weighs 370g, 54% (440g) lighter than the Laowa 17mm f4 TS's weight of 810g.
Below you can find the dimension and weight table of the Perspective Control Prime Lenses in Leica L Mount for size comparison purposes.
Ultra-Wideangle Lenses in Leica L Mount for Size Comparison
Filter Threads
The Laowa 17mm f4 TS has a filter size of 86mm whereas the Sigma 20mm F2 DG DN C has a 62mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 86mm filters that we recommend you to consider for the Laowa 17mm f4 TS:
And these are the 62mm filters that we recommend for the Sigma 20mm F2 DG DN C:
Lens Mounts
Both the Laowa 17mm f4 TS and the Sigma 20mm F2 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-P, Panasonic S1 II and Panasonic S1 IIE.
Laowa 17mm f4 TS is also available in the Sony E , Nikon Z and Canon RF mounts.
Sigma 20mm F2 DG DN C is also available in Sony E mount.
Focal Range
Laowa 17mm f4 TS is a prime lens with fixed focal lenght of 17mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
25.5mm.
On the other hand, the Sigma 20mm F2 DG DN C 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 30mm.
