24mm

24mm refers to a focal length used in photographic lenses. On 35mm-format cameras it is generally considered a wide-angle lens, delivering a broad field of view and a sense of spatial depth that suits landscapes, architecture, interiors, and environmental photography. The exact field of view depends on the sensor size: on a full-frame sensor (36x24 mm) a 24mm lens gives about 74 degrees horizontally, 53 degrees vertically, and roughly 84 degrees diagonally. On smaller sensors, the effective field of view is multiplied by the crop factor, so a 24mm lens behaves more like a longer focal length (for example about 36–38mm on many APS-C systems, and about 48mm on Micro Four Thirds).

Applications and characteristics: 24mm is favored for expansive scenes and tight spaces, where lines may converge toward the edges and perspective is emphasized. It yields a relatively large depth of field, especially when stopped down or focused at practical distances, making front-to-background elements appear sharp together. Distortion is a common trait of wide angles, with mild barrel distortion more noticeable toward the image edges; many modern cameras and lenses provide in-camera or post-processing corrections.

Lenses and variations: 24mm is available as primes (for example, 24mm f/1.4, f/2.8) and as part of zoom ranges (such as 24-70mm). Image quality, maximum aperture, and distortion control vary by design and brand, but the 24mm focal length remains a staple tool for photographers seeking a wide, relatively undistorted field of view without the extreme perspective of ultra-wide lenses.