Capturing Light : the Essence of Photography

Body Surfing, Nova Scotia © 2007 J. Martin

Any scene or image we see is created by light, either being emitted directly (fire, the sun, a light bulb) or indirectly reflecting off objects.

Humans have always treasured visual images, but until the 19^th century the only way to record an image was for an artist to render it in a medium such as paint or sculpture.

Only for the past 170 years or so have we been able to create permanent images by capturing light with photosensitive chemicals. And in the 20^th century humans invented a second way to capture images: electronic photo-sensors, first used in TV cameras and now in digital cameras.

A captured image is of course called a photograph, literally a "light picture". In this course, we'll learn the art of creating images that are beautiful, provocative, or artistically interesting for some other reason. Much of the process of capturing an image (taking a photograph) is very similar whether the capture medium is a digital sensor or photo-sensitive film.

Three Common Ways to Capture a Visual Image

1. Film: coat a clear plastic film with photosensitive chemicals, then expose it to light in a camera
2. Photo Paper: coat a piece of paper with photosensitive chemicals, then expose it to light in a darkroom using an enlarger
3. Digital camera: record a scene by focusing the light onto a electronic sensor, and store the light pattern in electronic memory.

You can learn more about the details how photochemistry and digital imaging work by following the appropriate links on the course index. For now, just remember that photography is the process of capturing the light and shadow in a visual image. It's an art that you could happily spend a lifetime perfecting!