The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 35mm f2 IS USM and the Canon 40mm f2.8 STM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Canon 35mm f2 IS USM is the longer of the two lenses at 63mm. The Canon 40mm f2.8 STM with a length of 22mm, is 41mm shorter. Besides being longer, the Canon 35mm f2 IS USM also has a larger diameter of 78mm compared to the Canon 40mm f2.8 STM's 68mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Canon 40mm f2.8 STM weighs 130g, 61% (205g) lighter than the Canon 35mm f2 IS USM's weight of 335g.
Filter Threads
The Canon 35mm f2 IS USM has a filter size of 67mm whereas the Canon 40mm f2.8 STM has a 52mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Canon 35mm f2 IS USM:
And these are the 52mm filters that we recommend for the Canon 40mm f2.8 STM:
Lens Mounts
Both the Canon 35mm f2 IS USM and the 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.
Focal Range
Canon 35mm f2 IS USM 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.
On the other hand, the 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.