The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Viltrox AF 56mm F1.2 Pro and the Sigma 17-40mm f1.8 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 17-40mm f1.8 is the longer of the two lenses at 116mm. The Viltrox AF 56mm F1.2 Pro with a length of 92mm, is 24mm shorter. On the other hand, the Viltrox AF 56mm F1.2 Pro has a larger diameter of 78mm compared to the Sigma 17-40mm f1.8's 73mm 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 17-40mm f1.8 weighs 535g, 6% (35g) lighter than the Viltrox AF 56mm F1.2 Pro's weight of 570g.
Filter Threads
Both the Viltrox AF 56mm F1.2 Pro and the Sigma 17-40mm f1.8 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
The Viltrox AF 56mm F1.2 Pro has the Nikon Z lens mount whereas the Sigma 17-40mm f1.8 has the Canon RF lens mount. Some of the latest released cameras that are compatible with these mounts are RED Komodo-X 6K Z, Nikon Z50 II and Nikon Z30 for the Nikon Z Mount and Canon R50 V, Canon R100 and Canon R50 for the Canon RF Mount.
Viltrox AF 56mm F1.2 Pro is also available in the Sony E and Fujifilm X mounts.
Sigma 17-40mm f1.8 is also available in Sony E , Leica L and Fujifilm X mounts.
Focal Range
Viltrox AF 56mm F1.2 Pro is a prime lens with fixed focal lenght of 56mm which has an effective (full-frame 35mm equivalent) focal range of
84mm when used on a APS-C / DX format camera.
On the other hand, the Sigma 17-40mm f1.8 has a focal range of 17-40mm and 2.4X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 27.2-64mm when used on a APS-C / DX format camera.
