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 realize greater sharpness and accurate rendering. Super Spectra coating has been applied to individual elements to minimize ghosting and flare for greater contrast and color neutrality when working in strong lighting conditions. An STM stepping AF motor realizes 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. 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.