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.
#http://en.wikipedia.org
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