Photography is all about capturing light – either on a film or a sensor (like the one in your camera and cell phone). The camera has some control over the amount of light that hits the sensor and the sensitivity of the sensor. The aperture and shutter speed control how much light is let through the lens. It’s a bit like your eye.
The aperture is like your pupil, dilating (getting larger) in low light and getting smaller in bright light.
The shutter speed is similar to a blink of an eye. Blink fast and only a small amount of light gets in. Blink slow and more light gets in.
ISO makes the sensor more or less responsive to light.
All three together make up the Exposure Triangle.
Whether or not you use automatic exposure settings, a little bit of knowledge about the exposure triangle will give you a better idea of what’s happening in there. And, it might give you the courage to do more with your camera. Higher shutter speeds will help you capture the action at the next soccer game. And, using a large aperture will give you a blurry background in your portrait shots. Try it out. Only takes a minute and you just might like what you see.
If you’d like a bit more info on the exposure triangle, check out this article from Digital Photo Secrets.