Cameras from large to small, film to digital

A camera is a device that records images. These images may be still photographs or moving images such as videos or movies. The termcamera comes from the camera obscura (Latin for "dark chamber"), an early mechanism for projecting images. The modern camera evolved from the camera obscura.

Cameras may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A camera generally consists of an enclosed hollow with an opening (aperture) at one end for light to enter, and a recording or viewing surface for capturing the light at the other end. A majority of cameras have a lens positioned in front of the camera's opening to gather the incoming light and focus all or part of the image on the recording surface. Most 20th century cameras used photographic film as a recording surface, while modern ones use an electronic camera sensor. The diameter of the aperture is often controlled by a diaphragm mechanism, but some cameras have a fixed-size aperture.

A typical still camera takes one photo each time the user presses the shutter button. A typical movie camera continuously takes 24 film frames per second as long as the user holds down the shutter button, or until the shutter button is pressed a second time.

The forerunner to the camera was the camera obscura. It was a dark chamber (in Latin, a camera obscura, demonstrating the etymology), "consist[ing] of a darkened chamber or box, into which light is admitted through a convex lens, forming an image of external objects on a surface of paper or glass, etc., placed at the focus of the lens". The camera obscura was described by the Arabic scientist Ibn al-Haytham (Alhazen) in his Book of Optics (1015–1021). The actual name of camera obscura was applied by mathematician and astronomer Johannes Kepler in hisAd Vitellionem paralipomena of 1604. He later added a lens and made the apparatus transportable, in the form of a tent. British scientistRobert Boyle and his assistant Robert Hooke developed a portable camera obscura in the 1660s.

The first camera obscura that was small and portable enough for practical use was built by Johann Zahn in 1685. At this time there was no way to preserve the images produced by these cameras apart from manually tracing them. However, in 1724, Johann Heinrich Schultz discovered that a silver and chalk mixture darkens under exposure to light. Early photography built on these discoveries and developments. The early photographic cameras were essentially similar to Zahn's camera obscura, though usually with the addition of sliding boxes for focusing. Before each exposure, a sensitized plate would be inserted in front of the viewing screen to record the image. The first permanent photograph was made in 1826 by Joseph Nicéphore Niépce using a sliding wooden box camera made by Charles and Vincent Chevalier in Paris and building on Johann Heinrich Schultz's discovery about silver and chalk mixtures darkening when exposed to light. Jacques Daguerre's popular daguerreotypeprocess utilized copper plates, while the calotype process invented by William Fox Talbot recorded images on paper.

Camera obscura

The development of the collodion wet plate process by Frederick Scott Archer in 1850 cut exposure times dramatically, but required photographers to prepare and develop their glass plates on the spot, usually in a mobile darkroom. Despite their complexity, the wet-plate ambrotype and tintypeprocesses were in widespread use in the latter half of the 19th century. Wet plate cameras were little different from previous designs, though there were some models, such as the sophisticated Dubroni of 1864, where the sensitizing and developing of the plates could be carried out inside the camera itself rather than in a separate darkroom. Other cameras were fitted with multiple lenses for making cartes de visite. It was during the wet plate era that the use of bellows for focusing became widespread.

The first color photograph was made by Scottish physicist James Clerk Maxwell, with the help of English inventor and photographer Thomas Sutton, in 1861

The electronic video camera tube was invented in the 1920s, starting a line of development that eventually resulted in digital cameras, which largely supplanted film cameras after the turn of the 21st century.