Size and Weight Comparison
Size of a lens is an important deciding factor when comparing two lenses.Carl Zeiss Distagon T1,4/35 is the longer of the two lenses at 120mm. The Canon 40mm f2.8 STM with a length of 22mm is 98mm shorter. Besides being longer, the Carl Zeiss Distagon T1,4/35 also has a larger diameter of 78mm compared to Canon 40mm f2.8 STM's 68mm diameter.
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 40mm f2.8 STM weighs 130g, 84% (700g) lighter than the Carl Zeiss Distagon T1,4/35's weight of 830g.
Both Carl Zeiss Distagon T1,4/35 and Canon 40mm f2.8 STM 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.
Carl Zeiss Distagon T1,4/35 is also available in Nikon F (FX) mount.
Carl Zeiss Distagon T1,4/35 is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides an 35mm (FF) equivalent of 56mm.
Canon 40mm f2.8 STM 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 an 35mm (FF) equivalent of 64mm.