Digital Cameras Are Similar to Film but Different

Like a film camera, the digital camera consists of a light-proof box with a lens, diaphragm, and shutter. The key difference is that in a digital camera the light is focused not onto film, but onto a photosensitive silicon chip or semiconductor, called an image sensor (see Figure 1-4).

Having an image sensor instead of film entirely changes things on the camera's back end. With film, once you capture the image, the only job left for the camera is to advance the film roll or cassette to the next unexposed frame. But with digital, pressing the shutter is only the beginning of a complex process that requires numerous other components and engineering considerations. Most digital cameras incorporate the following components (see also Figure 1-5):

■ Image sensor, to actually capture the photo

■ ADC (analog -to-digital converter) to create the digital data of the photo

■ Lots of digital circuitry, including one or more DSPs (digital signal processors) and one or more ASICs (application-specific integrated circuits), to process the data and create the image file

■ LCD viewfinder, for composing pictures, reviewing photos already shot, and accessing some commands and controls

■ Memory card slot and/or built-in memory, to save the digital image

■ USB port for connecting to a computer

■ Video out port for connecting to a TV or projector, where you can view your photos

■ AC adapter port, to try to save on the cost of batteries

Shutter button K View finder image sensor image sensor

Figure 1-4: Instead of film, digital cameras capture photographs using silicon chips called image sensors.

Get Paid to Take Digital Photos

Get Paid to Take Digital Photos

Reasonable care has been taken to ensure that the information presented in this book is  accurate. However, the reader should understand that the information provided does not constitute legal, medical or professional advice of any kind.

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