Recognisable by its truly thin profile, along with an advanced autofocus motor, the EF-S 24mm f/2.8 STM from Canon is a 38.4mm-equivalent prime designed for APS-C-format DSLRs. Its optical design features one aspherical element, which helps to reduce distortion and spherical aberrations for high sharpness and clarity. A Super Spectra coating has also been applied, which helps to minimise lens flare and ghosting for improved contrast and colour fidelity in bright lighting conditions. Additionally, benefitting both photo and video applications, an STM stepping AF motor is used to realise quick, accurate, and near-silent autofocus performance. 

Features:

Short normal-length prime is designed for use with APS-C-format Canon EF-S-mount DSLRs and provides a 38.4mm equivalent focal length.

Modestly bright f/2.8 maximum aperture benefits working in low-light affords control over depth of field and helps to keep the overall physical design compact and lightweight.

Pancake form factor measures less than 1"-thick for an ultra-portable, versatile design.

One aspherical element limits distortion and spherical aberration in order to realise greater sharpness and accurate rendering.

Super Spectra coating has been applied to individual elements to minimise ghosting and flare for greater contrast and colour neutrality when working in strong lighting conditions.

An STM stepping AF motor realises smooth, near-silent autofocus that is complemented by a rear focus system, advanced AF algorithms, and a high-speed CPU for fast AF performance. Additionally, full-time manual focus override is also available.

The rounded seven-blade diaphragm contributes to a pleasing out of focus quality that benefits the use of shallow depth of field and selective focus techniques.