The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Tamron SP 35mm F1.4 Di USD and the Voigtlander 40mm F2 SL II for their suitability to various photography scenarios:
Size and Weight Comparison
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 F2 SL II weighs 200g, 75% (605g) lighter than the Tamron SP 35mm F1.4 Di USD's weight of 805g.
Lens Mounts
Both Tamron SP 35mm F1.4 Di USD and Voigtlander 40mm F2 SL II has the same Nikon F (FX) lens mount. Some of the latest released cameras that are compatible with the Nikon F (FX) lenses are Nikon D6, Nikon D780 and Nikon D3500.
Tamron SP 35mm F1.4 Di USD is also available in Canon EF mount.
Voigtlander 40mm F2 SL II is also available in Canon EF and Pentax KAF mounts.
Focal Range
Tamron SP 35mm F1.4 Di USD is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides an 35mm (FF) equivalent of 52.5mm.
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 1.5x crop, it provides an 35mm (FF) equivalent of 60mm.