The forerunner of the camera was the camera obscura, used by artists, which made images with a lens, but could not record them. The earliest surviving photograph, an image recorded on to a surface of some kind, was taken by Frenchman Joseph Niépce in 1827. It was recorded on a metal plate coated with chemicals that changed very slowly where the image was light but not where it was dark. Photographic processes were soon improved by two inventors working independently without knowledge of each other's work: Frenchman Louis Daguerre and Englishman William Fox Talbot.

Nicéphore Niépce

The earliest surviving photograph was a view taken in 1827 by Frenchman Joseph Nicéphore Niépce (1765–1833) from the window of his home at Chalon-sur-Saône, near Beaune, France. Simple cameras, in which rays of light reflected from an object passed through a pinhole in a dark box to make an upside-down image on a screen inside, had been invented centuries earlier. The problem was how to make the image permanent. Niépce solved it by fitting his camera with a metal plate coated with a thin layer of bitumen (asphalt, the substance used to surface roads) and oil. After eight hours, a ghostly image formed on the plate.

William Fox Talbot

William Fox Talbot (1800–77) was unaware of both Niépce's or Daguerre's work. His 1835 photograph of a window at Lacock Abbey was the first made by the calotype process, in which the image is recorded as a negative in the camera, and is used to print positive photographs. This process allowed many copies of a photograph to be made. Paper coated with silver iodide was used in the process. But the grain of the paper (its texture) could be easily seen in the prints, making them lesser quality than daguerreotypes.

Eastman's Kodak
box camera

In 1888 American inventor George Eastman (1854–1932) introduced the easy-to-use Kodak box camera. It helped to make photography a popular hobby because the films could be sent away for developing. Eastman also produced the first roll films. A photographer no longer needed to carry around expensive plates and a darkroom for developing the image.

Digital cameras

The first digital camera was built by Steven Sasson, an engineer at Eastman Kodak, in 1975. It used an image sensor, called a charge-coupled device (CCD). This is a device that divides an image into pixels, measures the brightness and colour of each one, and digitizes the readings. By the mid-1990s, digital cameras were becoming commonplace, and 10 years later they had largely replaced film cameras. Today most mobile phones and all smartphones have an integrated digital camera.

X-ray photos

X-rays were discovered—accidentally—by German scientist Wilhelm Röntgen (1845–1923) in 1895. He found that a piece of cardboard coated with crystals of the salt barium platinocyanide glowed when a thermionic valve or vacuum tube (an early electronic device) was switched on in the same room, even when the tube was covered over with opaque cardboard. Röntgen guessed these mystery rays—to which he gave the temporary name X-rays—came from the tube. It was soon discovered that the invisible rays could pass through many materials, such as flesh, but not through metal or bone. Röntgen found that X-rays could expose photographic plates, and made the first X-ray photograph of his wife’s hand in December 1895.