The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon EF 50mm f/1.8 STM and the Voigtlander 40mm F2 SL II for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Canon EF 50mm f/1.8 STM is the longer of the two lenses at 39mm. The Voigtlander 40mm F2 SL II with a length of 25mm, is 14mm shorter. Besides being longer, the Canon EF 50mm f/1.8 STM also has a larger diameter of 69mm compared to the Voigtlander 40mm F2 SL II's 63mm diameter.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Canon EF 50mm f/1.8 STM weighs 159g, which means it is 41g (20%) lighter than the Voigtlander 40mm F2 SL II which has a weight of 200g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Canon EF Mount for size comparison purposes.
Standard Prime Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Canon EF 50mm f/1.8 STM and the Voigtlander 40mm F2 SL II has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Voigtlander 40mm F2 SL II is also available in Nikon F (FX) and Pentax KAF mounts.
Focal Range
Canon EF 50mm f/1.8 STM is a prime lens with fixed focal lenght of 50mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 80mm.
Voigtlander 40mm F2 SL II is a prime lens with fixed focal lenght of 40mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 64mm.