Digital camera
FOR MORE THAN 200 YEARS, CAMERAS recorded
pictures as chemical changes in silver-containing
substances, on a strip of flexible, celluloid film.
The digital camera records pictures in electronic
form. At its heart is a specialized integrated
circuit known as a charge-coupled device (CCD).
This has millions of micro-units known as pixels.
It works in the opposite way to a miniature
computer or TV screen. Instead of electric signals
making pixels shine, when light hits a pixel it
generates a tiny electrical signal, according to
the light's colour and brightness. The signals
from the CCD's millions of pixels are analogue:
they vary continuously in a wave-like fashion.
They are converted by a microchip to digital
codes of numbers, represented as on off electronic
pulses. The digital signals are processed and fed
to the camera's internal memory or a removable
memory device such as a data card or memory
stick. Photographs can be downloaded from a
digital camera to a computer via a cable or in
some cases a wireless link. Some digital cameras
automatically reduce blurring caused by camera
shake or fast movement, some can record video
clips as well as still pictures.
FOR MORE THAN 200 YEARS, CAMERAS recorded
pictures as chemical changes in silver-containing
substances, on a strip of flexible, celluloid film.
The digital camera records pictures in electronic
form. At its heart is a specialized integrated
circuit known as a charge-coupled device (CCD).
This has millions of micro-units known as pixels.
It works in the opposite way to a miniature
computer or TV screen. Instead of electric signals
making pixels shine, when light hits a pixel it
generates a tiny electrical signal, according to
the light's colour and brightness. The signals
from the CCD's millions of pixels are analogue:
they vary continuously in a wave-like fashion.
They are converted by a microchip to digital
codes of numbers, represented as on off electronic
pulses. The digital signals are processed and fed
to the camera's internal memory or a removable
memory device such as a data card or memory
stick. Photographs can be downloaded from a
digital camera to a computer via a cable or in
some cases a wireless link. Some digital cameras
automatically reduce blurring caused by camera
shake or fast movement, some can record video
clips as well as still pictures.
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