All Cameras Are Alike

The word photography literally means "writing with light." Photography as an art and a science has existed and evolved for about 170 years, give or take. It had a hundred births, in the cramped closets and kitchens of inventors and innovators who labored in absolute darkness, coating paper, metal, and glass surfaces with photosensitive silver salts, exposing them inside light-proof wooden boxes affixed with lenses appropriated and adapted from telescopes and eyeglasses, and then immersing them into witches' brews of caustic chemicals to develop and fix those images permanently. Although the process has been vastly improved and greatly refined through the years, film-based photography is still essentially the same as it was back in the 1830s.

At its most basic, photography requires a device that creates a photograph (see Figure 1-1). We call that device a camera, which is a box that captures the light reflected from a scene, person, or object and converts it into a tangible representation of that light, that is, a picture.

Shutter button

View finder

Figure 1-1: All cameras do essentially the same thing. Point the lens at a scene. Look at the scene through the camera's viewfinder. When you are satisfied with the composition you see in the viewfinder, press the shutter button. And you will end up with a photograph of that scene that looks very much like it did in the viewfinder.

Shutter button

View finder

Figure 1-1: All cameras do essentially the same thing. Point the lens at a scene. Look at the scene through the camera's viewfinder. When you are satisfied with the composition you see in the viewfinder, press the shutter button. And you will end up with a photograph of that scene that looks very much like it did in the viewfinder.

To do this, most cameras typically have the following components:

■ A lens for directing and focusing the light into the camera

■ A diaphragm for regulating the amount of light allowed to pass into the camera, as well as controlling the depth of field

■ A shutter for controlling the duration of the light passing through the camera

■ A button or shutter release that tells the camera when to take the picture

■ A photosensitive element (film or an electronic image sensor) to record the photo

■ All contained in a light-proof box

In addition, most modern cameras also have:

■ A window (or viewfinder) of some sort for the photographer to preview what the camera lens sees

■ A photoelectric light meter for calculating exposure settings

■ A built-in electronic flash or interface for connecting an external strobelight

■ An electronic sensor to regulate flash intensity and duration for proper exposure

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