The Lens

• Lenses like this one are often sold separate from the DSLR body.PhotoObjects.net/PhotoObjects.net/Getty Images
  
  The lens of a DSLR is similar to lenses found on many cameras. The lens determines how light enters the camera and how much. Lenses can allow a user to zoom long distances or allow greater quantities of light in darker situations. On SLR cameras, lenses are typically interchangeable, though the lens mounts are generally proprietary to each camera manufacturer.
  
  

The Shutter Mirror

• Unlike simple point-and-shoot cameras with an LCD screen, DSLR use a shutter mirror to display exactly what the lens see in real time. The shutter mirror sits behind the lens and, when a picture is taken, flips up quickly to allow the light to reach the actual image-making components. Settings in the camera can allow the mirror to remain "raised" for longer or shorter periods of time, referred to as the "exposure."
  
  

Low Pass Filter

• Once the shutter raises, the light energy that reaches the camera can include a variety of non-visible spectrum that will affect the image. The spectra, such as the ultraviolet or infrared, are filtered out by the low-pass filter.
  
  

The CMOS sensor

• The Complementary Metal Oxide Semiconductor is the chip that converts light signals into an array of digital information. The chip has a grid of diodes; each detects photons at the different points and instantly converts their energy into a particular voltage, which is instantly translated to the image processor.
  
  

The Digital Image Processor

• The very heart of digital photography is the digital image processor. These microchips take the data collected from the CMOS and arrange them into an image. The image processor is what gives the final image its overall quality and speed before it's written to the Compact Flash or Secure Digital card.