The Canon EF-S 24mm f / 2.8 STM is an ultra-thin pancake and is one of the least expensive lenses you can buy. At just 22.8mm thick, it’s also easy to carry around all day with no hassle.
It is a wonderful little companion for travel and street photography as it provides a viewing angle equivalent to 38mm on Canon APS-C DSLRs.
The lens exhibits vignetting at wide apertures as well as distortion, but both are easily fixed in software. Most importantly, the lens focuses precisely and provides consistently sharp and detailed images.
With its bargain price, take-anywhere size, and highly competent imaging performance, this lens deserves to be on the wish list of many Canon APS-C DSLR users.