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.

Sample flare test. The Voigtlander 35mm f1.5 Nokton and 35mm F2 Ultron doing best here.

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.