A camera is an optical instrument that captures a visual image. At a basic level, cameras consist of sealed boxes, with a small hole that allows light through to capture an image on a light-sensitive surface. Cameras have various mechanisms to control how the light falls onto the light-sensitive surface. Lenses focus the light entering the camera. The aperture can be narrowed or widened. A shutter mechanism determines the amount of time the photosensitive surface is exposed to light.
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, as determined by shutter speed, lens F-number, and scene luminance. Exposure is measured in 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 producing a flash of artificial light at a color temperature of about 5500 K to help illuminate a scene. A major 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.
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 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 let the photographer to take a photo of themselves, hence the name.
Light painting, painting with light,light drawing, or light art performance photography are terms that describe photographic techniques of moving a light source while taking a long exposure photograph, either to illuminate a subject or space, or to shine light at the camera to 'draw', or by moving the camera itself during exposure of light sources. Practiced since the 1880s, the technique is used for both scientific and artistic purposes, as well as in commercial photography.
Night photography refers to the activity of capturing images outdoors at night, between dusk and dawn. Night photographers generally have a choice between using artificial lighting and using a long exposure, exposing the shot for seconds, minutes, or even hours in order to give photosensitive film or an image sensor enough time to capture a desirable image. With the progress of high-speed films, higher-sensitivity digital sensors, wide-aperture lenses, and the ever-greater power of urban lights, night photography is increasingly possible using available light.
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.
Burst mode, also called continuous shooting mode, sports mode, continuous mode, or burst shot, is a shooting mode in still cameras where several photos are captured in quick succession by either pressing the shutter button or holding it down. This is used mainly when the subject is in successive motion, such as sports photography. The photographer can then select the best image of the group or arrange them in a sequence to study the transitions in detail.
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.
