The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 28mm f2.8 and the Canon 24mm f2.8 IS USM 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 24mm f2.8 IS USM is the longer of the two lenses at 56mm. The Canon 28mm f2.8 with a length of 43mm, is 13mm shorter. Besides being longer, the Canon 24mm f2.8 IS USM also has a larger diameter of 68mm compared to the Canon 28mm f2.8'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 28mm f2.8 weighs 185g, which means it is 95g (33%) lighter than the Canon 24mm f2.8 IS USM which has a weight of 280g.
Below you can find the dimension and weight table of the Wideangle Prime Lenses in Canon EF Mount for size comparison purposes.
Wideangle Prime Lenses in Canon EF Mount for Size Comparison
Both the Canon 28mm f2.8 and the Canon 24mm f2.8 IS USM 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 28mm f2.8 is a prime lens with fixed focal lenght of 28mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 44.8mm.
Canon 24mm f2.8 IS USM is a prime lens with fixed focal lenght of 24mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 38.4mm.