Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Voigtlander 40mm F1.4 Nokton Classic is the longer of the two lenses at 30mm. The Voigtlander 35mm F1.4 Nokton with a length of 29mm is 1mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 55mm.
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. Voigtlander 40mm F1.4 Nokton Classic weighs 175g, which means it is 25g (14%) lighter than the Voigtlander 35mm F1.4 Nokton which has a weight of 200g.
Both Voigtlander 40mm F1.4 Nokton Classic and Voigtlander 35mm F1.4 Nokton has the same Leica M lens mount. Some of the latest released cameras that are compatible with the Leica M lenses are Leica M11, Leica M10 and Leica M Typ 262.
Voigtlander 40mm F1.4 Nokton Classic is a prime lens with fixed focal lenght of 40mm. Voigtlander 35mm F1.4 Nokton is a prime lens with fixed focal lenght of 35mm.