Digital Camera
A digital camera (or digicam)
is a camera that takes video or still photographs, or both, digitally
by recording images via an electronic image sensor. It is the main
device used in the field of digital photography. Most 21st century
cameras are digital.
Digital
cameras can do things film cameras cannot: displaying images on a screen
immediately after they are recorded, storing thousands of images on a
single small memory device, and deleting images to free storage space.
The majority, including most compact cameras, can record moving video
with sound as well as still photographs. Some can crop and stitch
pictures and perform other elementary image editing. Some have a GPS
receiver built in, and can produce Geotagged photographs.
The
optical system works the same as in film cameras, typically using a
lens with a variable diaphragm to focus light onto an image pickup
device. The diaphragm and shutter admit the correct amount of light to
the imager, just as with film but the image pickup device is electronic
rather than chemical. Most digicams, apart from camera phones and a few
specialized types, have a standard tripod screw.
Digital
cameras are incorporated into many devices ranging from PDAs and
mobile phones (called camera phones) to vehicles. The Hubble Space
Telescope and other astronomical devices are essentially specialized
digital cameras.
Digital cameras
are made in a wide range of sizes, prices and capabilities. The
majority are camera phones, operated as a mobile application through
the cellphone menu. Professional photographers and many amateurs use
larger, more expensive digital single-lens reflex cameras (DSLR) for
their greater versatility. Between these extremes lie digital compact
cameras and bridge digital cameras that "bridge" the gap between
amateur and professional cameras. Specialized cameras including
multispectral imaging equipment and astrographs continue to serve the
scientific, military, medical and other special purposes for which
digital photography was invented.
