Overriding Auto-Exposure
Auto-exposure is a marvel of camera technology, the result of years of development work by talented R&D teams. But there are times when we’d rather dump the auto-exposure technology and use manual settings. This may be under unusual lighting conditions or for creative work - roughly 20 per cent of the time for many users.
The more expensive cameras have manual over-ride, but if your camera doesn’t have this facility, it is still possible to exert your control and get the camera to do your bidding, not the other way round! Auto exposure controls are generally adjusted for the average, but many routine pictures have characteristics that fall outside the average, such as a bright sky and a dark foreground. The average exposure is often below the correct level for the sky, so it comes out white, and above the correct level for the foreground, so it comes out dark. In this case, we can manipulate the camera and get it to do our bidding.
To expose correctly for the sky, aim the camera at the sky, lightly hold down the shutter, reposition it and take the shot. To expose correctly for the dark foreground, aim the camera down, and do the same. We now have two pictures that can be merged into one in image editing later
Many cameras have auto-exposure compensation. However, if you’re aiming at a dark subject against a light background, then you can set the compensation to the plus setting, making it overexpose, and vice versa. Apart from switching off the flash, there’s not much you can do to manipulate the autoexposure settings, so if you really want to take control, then it may be an idea to get a higher specification camera.
