Photograph

A photograph is an image made by light striking a photosensitive surface, either photographic film or an electronic image sensor like a CCD or CMOS chip. It is also referred to as a photo, image, or picture. Nowadays, the majority of photos are taken with a smartphone/camera, which employs a lens to concentrate the scene's visible light wavelengths into a replica of what the human eye would perceive. Photography is the art and science of producing such images.

Nicéphore Niépce's "heliography" process, which relies on bitumen, was used to create the first-ever permanent photograph, a contact-exposed replica of etching, in 1822. A few years later, in 1826, at Le Gras, France, the first images of a real-world scene were captured using a camera obscura, although Niépce's method was not sensitive enough to be useful in that application; a camera exposure lasting for hours or days was necessary. Niépce and Louis Daguerre formed a collaboration in 1829, and the two men worked together to develop a similar but superior procedure.

Daguerre focused on silver halide-based substitutes after Niépce's passing in 1833. He developed a layer of light-sensitive silver iodide on a silver-plated copper sheet by exposing it to iodine vapor, then exposed it to the camera for a short period of time, developed the resulting latent image to visibility with mercury fumes, and finally submerged the plate in a hot salt solution to remove the remaining silver iodide, making the results light-fast. He gave his own name, Daguerre, to the first practical method for creating images taken with a camera. On January 7, 1839, the world was informed of its existence, but it wasn't until August 19 that the workings were made known. Portrait photography became genuinely feasible and very well-liked when other innovators produced advancements that decreased the necessary exposure time from a few minutes to a few seconds.