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Use daylight for pure white backgrounds
It’s a useful technique to be able to create a brilliant white background in an outdoor situation. People assume this effect is only possible using studio lighting, but the truth is that it can easily be achieved simply using daylight and minimal equipment. The principle is the same: to achieve a brilliant white backdrop involves correctly exposing the subject while overexposing the background by anything from one to three stops. To do this, you need to be able to control how the sunlight falls on the scene – this is achieved by using a diffusing panel. By placing the diffuser between the subject and the sun, you not only soften the light, but also reduce how much light reaches the subject so that the correct exposure for the subject will be significantly less than for the background, which will naturally overexpose and record as pure white.
WHITEOUT
When taking a picture like this, choose a background with light tones and ensure that the backdrop is fully illuminated by the sun. You can determine the amount of light loss caused by the diffuser, as most diffuser panels state it; the diffuser used here had a –2-stop effect. Using the spot meter in the camera, or taking a reading with a handheld meter positioned in front of the face, you will take the perfect exposure for the subject. And, because the backdrop is lit directly by the sun, it will receive a higher exposure and so will bleach out to white. In this example, when the meter reading from the subject’s face lit by diffused light was 1/250 at f/4, the background was two stops brighter – in other words, 1/250 at f/8. By setting the camera to 1/250 at f/4, we correctly exposed the model’s face but overexposed the background by two stops.
Canon EOS 10D, 28–70mm lens at 70mm, 1/1000 sec at f/2.8, ISO 100.