Light enters the camera by way of the lens, which focuses the light beams so that they fall correctly onto the photographic medium – which, in the case of digital cameras, is a sensor called a charge-coupled device, or CCD for short. On its way through the lens, the light will also pass through the camera’s aperture, a scalable “hole” that adjusts the amount of light that passes through the lens. The final barrier is the shutter, which opens when the camera’s shutter button is depressed, allowing the light rays to strike the CCD. The amount of time that the shutter stays open can be varied, allowing more or less light to reach the CCD. The exposure of the photograph is determined by combining the aperture and shutter (or more correctly, shutter speed) settings. These, in combination with the current sensitivity of the CCD (which is measured in terms of an ISO rating) will determine whether the photo is under or overexposed (too dark or too light, respectively) or turns out just right. A further setting, called white balance, will ensure that the camera accurately recreates colours in the photograph. While focus, aperture, shutter speed, ISO and white balance can be automatically determined by the camera, these automated settings are based on averages. Once again, the camera does not have a brain, and is never aware of what exactly the photographer wants the final picture to look like. However, by adjusting some – or all – of these elements, the photographer will have more direct control over the final outcome. But control means compromise – at least in photographic terms – and the photographer will need to alter what can sometimes be a delicate balance established between the basic elements above. This is particularly the case when it comes to aperture and shutter speed which, in combination, have a very direct effect not only on the exposure of the photograph, but also on numerous other elements that could make or break a picture. We will look at all of these elements in this section of Gladget Magazine, as well as exploring on more advanced techniques, tips and ideas. Initially, though, our first piece of advice is that photographers find out how their camera functions by reading the manual that came with it. Additionally, getting into the habit of recording conditions and settings when taking photographs is a good step – each picture, whether good or bad, can not only speak a thousand words, but can also teach a thousand lessons. In the next issue, we will begin investigating the relation of aperture and shutter speed to the final picture. We will also start looking at basic photo-manipulation using well known, PC-based software.g gladget feature • issue 1 • October 2010
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