Red eye

When you look at someone's face the pupil in the center of each eye appears naturally black. In actual fact, the light-sensitive retina at the back of the eye is pink, but is too recessed and shaded to appear colored under normal lighting conditions. However, the flash that is built into a small camera body is only displaced an inch or so to one side of the lens. Like an optician's lamp used to closely examine eyes, the flash easily lights up that part of the retina normally seen as dark. The result is portraits showing 'red eye'.

Camera designers go to great lengths to minimize the defect - the flash source often slides out or hinges up (Figure 26.1) to locate it further from the lens. Another approach is to make the flash give one or more flickering 'pre-flashes' just before flashing at full power with the shutter. This is done to make the eyes of whoever you are photographing react by narrowing their pupil size, which in turn results in reducing the occurrence of red eye.

In addition to these techniques, you can help minimize red eye by angling the camera to avoid straight-on portraits. This may also avoid glare from any reflective surfaces square-on in the background. You may even be able to diffuse and so spread the light with a loop of tracing paper over the flash window. But the best approach of all, if your camera accepts an add-on flashgun, is to 'bounce' the light and avoid red eye altogether.

Digital Camera and Digital Photography

Digital Camera and Digital Photography

Compared to film cameras, digital cameras are easy to use, fun and extremely versatile. Every day there’s more features being designed. Whether you have the cheapest model or a high end model, digital cameras can do an endless number of things. Let’s look at how to get the most out of your digital camera.

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