What are the basics of a camera?

By Aaron Raisey

A camera is, in its essence, a very simple tool. It’s just a box that allows a measured amount of light to fall upon a light-sensitive recording surface. Unfortunately this basic simplicity has become increasingly camouflaged behind buttons and functions, hardware and software. Though the modern camera offers many creative options to savvy users, to others it’s just a black box requiring little or no understanding of the basic principles involved. Of course, understanding (or not) of the fundamentals of the photographic process has never stood in the way of someone’s ability to create a good picture, but an appreciation of what that camera actually does at that fundamental level can add new dimensions to your photography and give you many avenues of creativity to explore.

Over the next several editions of this column, we’ll explore the most important functions of the camera and examine how they come together and impact our photography and photographs. It seems that most everyone has a DSLR these days, so we’ll use that kind of camera as our point of reference. The principles involved are readily transferred to other kinds of cameras in any case. This week, a general overview will give us the important background to take forward through the next few weeks.

Two things come together at the heart of the camera body; shutter speed and aperture (though the aperture is actually in the lens). The speed of the shutter controls the amount of light entering the camera by way of time spent open, and the aperture by the size of the hole through which the light passes. The relationship between these two, or the way they combine to regulate the light falling on the image sensor is called the “exposure.”

The look of an image _ the creative options presented by varying the shutter speed and/or the aperture _ is affected by how much time the shutter remains open, and how big or small the aperture is.

With a DSLR we can isolate these two elements and adjust their values. You can do this easily yourself if you have a DSLR handy. Click into TVmode and adjust the shutter speed. See how the aperture value gets bigger and smaller to compensate and maintain optimal exposure. Switch to Av mode to focus on the aperture. Adjusting the aperture results in the speed of the shutter getting faster as the aperture gets bigger or slower as it closes _ the exposure remains at an ideal level.

These elements _ shutter speed and aperture _ we will examine much more closely. Knowing how to exploit the relationship between these important concepts will give you some clues as to how the pros achieve effects like motion blur or out-of-focus backgrounds - things you may have tried to emulate - and unlock some interesting and exciting new adventures in your photography.

This week’s image from Brian Keathley shows the effects of a long shutter speed and a small aperture.

Get out there, experiment a lot, then shoot some more, and head on over to the Seoul Photo Club to see examples of great expat photography and get some tips and advice from the best expat photographers in Korea.

Aaron Raisey is the leader of the Seoul Photo Club on Flickr (www.flickr.com/groups/seoulphotoclub), Korea’s premier expat photography society. If you have any questions or inquiries you can contact him at aaron.raisey@gmail.com.