What does "exposure of the image" mean and how does it affect my digital camera's photos?

What does "exposure of the image" mean and how does it affect my digital camera's photos?

Mark Comon (Vice President, Paul's Photo, Torrance, CA) gives expert video advice on: What does my digital camera's "manual exposure" mode allow me to do?; How do I change the shutter speed on my digital camera?; Which is worse to overexpose or underexpose pictures on my digital camera? and more...

In photography, the term "exposure" refers to how we control the lightness and the darkness of the image. The exposure is controlled by the camera's light meter. Whether you control the light meter yourself or you let the camera do the light metering for you, it all sets the F-stop and shutter speed. I know for a lot of you, those are scary words, but we always do F-stops and shutter speeds on every picture to get the light right or the lightness and darkness and exposure. A good way to think about exposure is just like steak. Some people like their steaks rare; some people like their steaks well done. Exposure or lightness and darkness in the picture is a combination of the F-stop, which is the size of the hole in the lens, and the shutter speed, which is the length of time that the shutters open. So, if you think about it, if we leave the shutter open longer, we're getting more light to the film or more light to the digital sensor, so the picture gets brighter, or lighter. If we shorten the exposure (give less light to the film or to the digital sensor), the exposure gets darker. Longer shutter speed: more exposure, more light; shorter shutter speed: less exposure, less light.