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.
The 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.
From its inception, the camera has been instrumental in the recording of still images from then-present surroundings, and further modifications led to the development of motion picture sequences in the late 19th century. Cameras and the exhibition of camera-captured images are widely used in both professional and consumer settings in the 21st century for both mass and interpersonal communication