The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 40mm f2.8 STM and the Canon 35mm f2.0 for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Canon 35mm f2.0 is the longer of the two lenses at 43mm. The Canon 40mm f2.8 STM with a length of 22mm, is 21mm shorter. On the other hand, the Canon 40mm f2.8 STM has a larger diameter of 68mm compared to the Canon 35mm f2.0's 67mm diameter.
The 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, which means it is 80g (38%) lighter than the Canon 35mm f2.0 which has a weight of 210g.
Both the Canon 40mm f2.8 STM and the Canon 35mm f2.0 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.
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 a 35mm (FF) equivalent of 64mm.
Canon 35mm f2.0 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 a 35mm (FF) equivalent of 56mm.