A camera is an instrument used to capture and store images and videos, either digitally via an electronic image sensor, or chemically via a light-sensitive material such as photographic film. As a pivotal technology in the fields of photography and videography, cameras have played a significant role in the progression of visual arts, media, entertainment, surveillance, and scientific research. The invention of the camera dates back to the 19th century and has since evolved with advancements in technology, leading to a vast array of types and models in the 21st century.
In photography, shutter speed or exposure time is the length of time that the film or digital sensor inside the camera is exposed to light when taking a photograph. The amount of light that reaches the film or image sensor is proportional to the exposure time. 1⁄500 of a second will let half as much light in as 1⁄250.
In photography, exposure is the amount of light per unit area reaching a frame of photographic film or the surface of an electronic image sensor. It is determined by shutter speed, lens f-number, and scene luminance. Exposure is measured in units of lux-seconds, and can be computed from exposure value (EV) and scene luminance in a specified region.
A flash is a device used in photography that produces a brief burst of light at a color temperature of about 5500 K to help illuminate a scene. The main purpose of a flash is to illuminate a dark scene. Other uses are capturing quickly moving objects or changing the quality of light. Flash refers either to the flash of light itself or to the electronic flash unit discharging the light. Most current flash units are electronic, having evolved from single-use flashbulbs and flammable powders. Modern cameras often activate flash units automatically.
In photography, flash synchronization or flash sync is the synchronizing the firing of a photographic flash with the opening of the shutter admitting light to photographic film or electronic image sensor.
In photography and cinematography, a multiple exposure is the superimposition of two or more exposures to create a single image, and double exposure has a corresponding meaning in respect of two images. The exposure values may or may not be identical to each other.
The science of photography is the use of chemistry and physics in all aspects of photography. This applies to the camera, its lenses, physical operation of the camera, electronic camera internals, and the process of developing film in order to take and develop pictures properly.
Chronophotography is a photographic technique from the Victorian era which captures a number of phases of movements. The best known chronophotography works were mostly intended for the scientific study of locomotion, to discover practical information for animal handlers and/or as reference material for artists. Although many results were not intended to be exhibited as moving pictures, there is much overlap with the more or less simultaneous quest to register and exhibit photographic motion pictures.
Time-lapse photography is a technique in which the frequency at which film frames are captured is much lower than the frequency used to view the sequence. When played at normal speed, time appears to be moving faster and thus lapsing. For example, an image of a scene may be captured at 1 frame per second but then played back at 30 frames per second; the result is an apparent 30 times speed increase.
A rotary disc shutter is a type of shutter. It is notably used in motion picture cameras. Rotary shutters are semicircular discs that spin in front of the film gate, alternately allowing light from the lens to strike the film, or blocking it.
In photography, a shutter is a device that allows light to pass for a determined period, exposing photographic film or a photosensitive digital sensor to light in order to capture a permanent image of a scene. A shutter can also be used to allow pulses of light to pass outwards, as seen in a movie projector or a signal lamp. A shutter of variable speed is used to control exposure time of the film. The shutter is constructed so that it automatically closes after a certain required time interval. The speed of the shutter is controlled either automatically by the camera based on the overall settings of the camera, manually through digital settings, or manually by a ring outside the camera on which various timings are marked.
The Bulb setting on camera shutters is a momentary-action mode that holds shutters open for as long as a photographer depresses the shutter-release button. The Bulb setting is distinct from shutter's Time (T) setting, which is an alternate-action mode where the shutter opens when the shutter-release button is pressed and released once, and closes when the button is actuated again.
A self-timer is a device on a camera that gives a delay between pressing the shutter release and the shutter's firing. It is most commonly used to allow the photographer to take a photo of themselves, hence the name.
The following outline is provided as an overview of and topical guide to photography:
Sports photography refers to the genre of photography that covers all types of sports.
Zoom burst is a photographic technique, attainable with zoom lenses with a manual zoom ring.
Long-exposure, time-exposure, or slow-shutter photography involves using a long-duration shutter speed to sharply capture the stationary elements of images while blurring, smearing, or obscuring the moving elements. Long-exposure photography captures one element that conventional photography does not: an extended period of time.
Most digital cameras support the ability to choose among a number of configurations, or modes for use in various situations. Professional DSLR cameras provide several manual modes; consumer point-and-shoot cameras emphasize automatic modes; amateur prosumer cameras often have a wide variety of both manual and automatic modes.
In intentional camera movement (ICM), a camera is moved during the exposure for a creative or artistic effect. This causes the image points to move across the recording medium, producing varied effects such as streaking, textures, and layers in the resulting image. The central idea in ICM photography is that motion serves as the primary compositional element. Strict technical or definitional arguments remain vague in this form of photography which has a long history and is connected with many other forms of photography, such as Impressionism and often blurs genres and styles.
A star trail is a type of photograph that uses long exposure times to capture diurnal circles, the apparent motion of stars in the night sky due to Earth's rotation. A star-trail photograph shows individual stars as streaks across the image, with longer exposures yielding longer arcs. The term is used for similar photos captured elsewhere, such as on board the International Space Station and on Mars.
