1. An Explanation of Digital
Photography
By Mark W. Decker

2. Introduction
• An avid photographer, Mark W. Decker takes care to
understand the mechanisms that work within a camera.
Mark W. Decker stands out as a skilled user of many
types of digital camera.
On a fundamental level, the digital camera works much
like a film camera does. Light enters the device through
an opening called the aperture, and a lens focuses this
light to enable image exposure. Rather than capture this
image on traditional film, however, the digital camera
transmits the image to a silicone sensor. This sensor
consists of millions of small photosites that accumulate
an electrical charge based on the level of brightness in
the light that it perceives.

3. Digital Photography
• When a photosite receives light, it absorbs
photons and releases electrons to a potential
well within the sensor. The electrons then collect
to generate an electrical charge that converts to a
particular analog voltage. After the camera
amplifies the total voltage, an A-to-D converter
transforms it into a number in binary code. This
code gives the camera the instructions that it
needs to select brightness and color on
corresponding pixels, which combine to form the
final image.