How Digital Cameras Work

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How Digital Cameras Work
By Erin Van Seeters
13/14
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Digital Cameras

• They depend entirely on chemical and mechanical
  processes.

• No electricity is needed.

• They are beginning to replace conventional
  cameras.

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Digital Images
A digital image is a long string of 1s and
0s that represent pixels. Or the colored dots
that make up the picture.
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Filmless Camera

• Instead of film a digital camera has a sensor
  that converts light into electrical charges.

• The most common image sensor is the charged
  couple device (CCD). Some cameras use
  complementary metal oxide semiconductors (CMOS).
  Where they then convert light into electrons.

• Once the light is converted into electrons it
  reads the value of each cell in the image.

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Resolution of Pictures

• The resolution is the amount of detail a camera
  can capture.

• The more pixels a camera has the more detail it
  can capture and the larger a picture can become
  without getting blurry.

• Very cheap cameras can have about 65,000 pixels
  while some professional cameras can have up to 20
  million pixels.

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Color

• The photosite, a circuit on a digital camera's
  sensor that transforms light energy to electrons
  is colorblind. It only keeps track of the total
  intensity of the light that strikes its surface.

• To get a full color image the sensors can use
  filtering to look at the light in its three
  primary colors. Once the camera records all three
  colors, it combines them to create the full
  spectrum.

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Recording Colors
Some ways to record colors are by using a beam
splitter, rotating the filters, or a color filter
array.
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Amount Of Light

• The aperture and the shutter speed help control
  the amount of light that reaches the sensor.

• The aperture is size of the opening in the
  camera. It is usually manual. And the shutter
  speed is the amount of time that light can pass
  through the aperture.

• They work together to capture the amount of light
  needed to make a good image.

• The camera also adjusts the lenses to control
  how the light is focused on the sensor.

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Lenses

• The focal length, the distance between the lens
  and the surface of the shutter determines the
  zoom. Increasing the focal length increases the
  magnification and objects appear closer. And
  decreasing the focal point, decreases the
  magnification and makes objects appear farther
  away.

• Digital cameras have one of four types of
  lenses the fixed-focus, fix zoom lenses, the
  optical zoom lenses with automatic focus,
  digital- zoom lenses or the replaceable lens
  systems.

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Storage Systems

• Storing pictures is like reusable, digital film
  and they use a card reader to transfer data onto
  a computer. Many involve flash memory such as
  Memory Sticks, or Smart Media cards.

• Cameras need a lot of room to store images. You
  can store them in an uncompressed format or a
  compressed format.

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Bibliography
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