Photographs

Photographs are images created by recording light or other electromagnetic radiation onto a photosensitive surface or digital sensor. They document scenes, people, and objects and serve artistic, documentary, scientific, and personal purposes.

The history of photography began in the 19th century with early chemical processes such as heliography, the daguerreotype, and the calotype. Improvements to film and lenses in the late 1800s and early 1900s broadened accessibility, while color processes emerged in the 20th century. The digital era, starting in the late 20th century, shifted production from chemical development to electronic sensors and computer-based processing.

A photograph is produced when a camera forms an image by letting light through a lens onto a photosensitive medium. Exposure is governed by aperture, shutter speed, and sensitivity. In film, the latent image is developed chemically; in digital cameras the sensor records electrical signals that are processed into image files.

Photographs vary by genre and format, including documentary, portrait, landscape, street, macro, and scientific imaging. They may be captured on film or digitally, in color or monochrome, and printed or viewed on screens. Common formats include JPEG and RAW for digital images, and various print sizes for physical copies.

Recording and preserving photographs involves metadata, archiving practices, and consideration of copyright and privacy. Ethical use includes obtaining consent for images of people and respecting intellectual property when reproducing works. Photographs provide historical documentation, aid scientific analysis, and contribute to visual storytelling.