photograph

A photograph is an image produced by capturing light on a photosensitive surface using a camera. The result records a moment, scene, or subject and can be viewed as prints, digital files, or on screens.

Etymology: photograph comes from the Greek photos, light, and graphé, drawing. The term and practice emerged in the early 19th century as scientists explored light-sensitive materials.

History: Early experiments in capturing images began in the 1820s and 1830s. The daguerreotype (1839) and the calotype introduced practical image-making. The late 19th century saw roll film and mass cameras, while the 20th century refined color processes and, later, digital photography.

Process and technology: In most cameras, light is focused through a lens onto a photosensitive surface. For film, the latent image is chemically developed and printed. In digital cameras, a sensor converts light to electrical signals to form a digital file, typically RAW or JPEG. Exposure is controlled by aperture, shutter speed, and ISO.

Equipment and formats: Cameras range from smartphones and compact cameras to DSLR, mirrorless, and rangefinder systems. Lenses alter perspective and light, while sensors vary in size. Common file formats include RAW for editing flexibility and JPEG for direct use.

Uses and genres: Documentary, portrait, landscape, street, macro, architectural, and astronomical photography cover diverse subjects. Photography supports journalism, science, art, and personal memory. Color and monochrome work involve stylistic choices and, with digital workflows, substantial post-processing.

Impact and issues: Photography shapes culture and communication and plays a key role in science, research, and history. It also raises ethical questions about consent, copyright, manipulation, and privacy, while archival standards help preserve images for the future.