Quick comparison between the Voigtlander 35mm f1.5 Nokton, Voigtlander 35mm f2 Ultron, Voigtlander 40mm f1.2mm Nokton and 7Artisans 35mm f2 WEN. Original files for download here. Images taken with the Leica SL2-S under same lighting conditions as well as white balance settings.
Voigtlander Nokton 35mm f1.5 at f1.5
Voigtlander Nokton 40mm f1.2 at f1.2
Voigtlander Ultron 35mm f2 at f2
7Artisans 35mm f2 WEN at f2
Sample flare test. The Voigtlander 35mm f1.5 Nokton and 35mm F2 Ultron doing best here.
Voigtlander Nokton 35mm f1.5 flare
Voigtlander Ultron 35mm f2 flare
Voigtlander Nokton 40mm f1.2 flare
7Artisans 35mm f2 WEN flare
Below samples are with every lens at f5.6 to even out the playing field. One can see the similar overall look of the two 35mm lenses with the 40mm showing a shallower depth of field. The 7Artisans 35mm lens showing flaring and poorer overall performance.
Voigtlander Nokton 35mm f1.5 at f5.6
Voigtlander Ultron 35mm f2 at f5.6
Voigtlander Nokton 40mm f1.2 at f5.6
7Artisans 35mm f2 WEN at f5.6