The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 24mm F2.8 STM and the Canon 28mm f1.8 USM 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 28mm f1.8 USM is the longer of the two lenses at 56mm. The Canon 24mm F2.8 STM with a length of 23mm, is 33mm shorter. Besides being longer, the Canon 28mm f1.8 USM also has a larger diameter of 74mm compared to the Canon 24mm 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 24mm F2.8 STM weighs 125g, which means it is 185g (59%) lighter than the Canon 28mm f1.8 USM which has a weight of 310g.
Filter Threads
The Canon 24mm F2.8 STM has a filter size of 52mm whereas the Canon 28mm f1.8 USM has a 58mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 52mm filters that we recommend you to consider for the Canon 24mm F2.8 STM:
And these are the 58mm filters that we recommend for the Canon 28mm f1.8 USM:
Lens Mounts
The Canon 24mm F2.8 STM has the Canon EF-S lens mount whereas the Canon 28mm f1.8 USM has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are Canon T8i, Canon 90D and Canon SL3 for the Canon EF-S Mount and Canon 1D X III, Canon 6D MII and Canon 5D MIV for the Canon EF Mount.
Focal Range
Canon 24mm F2.8 STM is a prime lens with fixed focal lenght of 24mm which has an effective (full-frame 35mm equivalent) focal range of
38.4mm when used on a APS-C / DX format camera.
On the other hand, the Canon 28mm f1.8 USM 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.