Overexposure is a term often discussed in photography. What does it mean?
Simply put, it is when too much light is allowed to reach the sensor and the resulting image is too light or bright.
Why does it happen?
To get a decent image, the camera has to select a combination of aperture (the size of the hole in the lens that lets in light) and shutter speed (the length of time the sensor is exposed to the light when taking a picture).
Generally, the camera chooses the correct combination. Sometimes the camera makes a wrong judgement for the scene in front of it OR the photographer chooses settings that are not ideal.
If this happens, too much light can enter the camera and hit the sensor, resulting in overexposure. The whites or highlights will be burnt out and too bright. Any detail in these areas will tend to be lost.
The cure is to retake the photograph and choose LESS exposure by using a smaller aperture or a faster shutter speed. This can be done either manually by the photographer or automatically by the camera if it has facility for automatic exposure compensation. Read the manual to find out.
Your images might also be overexposed if there is a good deal of low light in the scene you are photographing as the camera tries to compensate for the average low light levels by increasing the light hitting the sensor. Alternatively, using flash, especially the in-built flash on compacts and lower end prosumers / SLRs can result in overexposure and bleaching of your subjects. In these cases try to compensate using the camera.
Eric Hartwell runs the photography resource site http://www.theshutter.co.uk and the associated discussion forums as well as the regular weblog at http://thephotographysite.blogspot.com.
