How a Digital Camera
Works
by Jakob Jelling
The digital camera is not something of a magic box that came out
of the blue and made wonders! The digital camera is very much like the
conventional analog camera, but the technology has been altered. It also
contains most of the associated components that the conventional camera
contains, like lens and a shutter for letting in light, however instead of
reaching a photosensitive film, the light is made to fall upon array of image
sensors or photosensitive cells. Much of the differences are like this, yet
most of it still remains in oblivion for the ordinary people. And it order that
the digital camera gets its true respect, it is necessary to explore these
areas of truth and reveal them in light.
Looking a bit more in details about the working of the fantastic
device, the digital camera. As a continuation of the above lines, it can be
further investigated that the sensor array is basically a microchip about 10 mm
across. Every image sensor is a charged-couple device (CCD) converting light
into electric charges, and is essentially a silicon chip used to measure light.
These charges are stored as analog data that are then converted to digital via
a device called an analog to digital converter (ADC). Over the chip are present
a collection of very small light-sensitive diodes, named photosites, or pixels
that convert light (or more scientifically, photons) into electrical charges
called electrons. The pixels are very much light sensitive, therefore with
brighter light striking them, produces greater build up of electrical charges.
Each 1000 array receptor creates 1 pixel, and every pixel corresponds to some
information stored. The light enters the digital camera via the lens, which is
the same mechanism as the conventional analog camera. And this light hits the
CCD when the photographer presses the shutter button. The shutter opens and
thereby illuminates every pixel, however with various intensities.
Taking a look apart, it can be observed that quite a few digital
cameras use CMOS (meaning complementary metal oxide semiconductor, a technology
of manufacturing these microchips) technology based microchips as image
sensors. The basic advantage is that the CMOS sensors are appreciably cheaper
and simpler to fabricate than CCDs. Another great advantage from CMOS sensors
is that these take very less power compared to other technology, which adds up
to the fact as to their extensive use, and can thus even support the
implementation of additional circuitry on the same chip like ADC, some control
units etc. Thus it can be stated that CMOS technology based cameras are small,
light, cheap and also energy efficient, yet at the cost of some amount of image
quality.
However the common trend remains that all cameras of the mega
pixel range and higher up use CCD chips instead of CMOS. This is because of the
fact of picture quality only, leaving aside the price differences.
This is basically the fact about how digital cameras work!
Having known this much difference would not come in the photographing expertise
of the users, but it always feels a kind of satisfaction on understanding the
inner depths of a device that is so close to the eyes!
About the Author
Jakob Jelling is the founder of
http://www.snapjunky.com. Visit his digital camera guide
and learn how to take better pictures with your digicam.
Article
Source: http://www.bigarticles.com