The Basics of How a Camera Works
When you snap a picture you most likely expect the camera to capture the scene in front of you exactly as you see it. This rarely happens without some help. The camera is a great tool, but it needs your help to capture what your eyes are seeing.
Color
Your eyes constantly adjust to the changes in light as you move from one lighting situation to another. The color we see is a simple reflection from the object, and our eyes adjust to different lighting situations to see the same color no matter what.
An example might be walking inside your home on a bright, sunny afternoon. Your jeans will remain the same color blue as your eyes adjust, but this does not hold true for your camera. If the settings on your camera are not changed once you come inside, the resulting photo will not come out right.
Light
When you move from one light source to another, you have to help your camera adjust. This might mean changing white balance, film type or amount of exposure.
The amount of light a photo needs to come out clearly is greater than what our eyes need to see. The pupils in our eyes dilate to allow extra light in when needed. They adjust on their own, requiring no thought on our part. You will however, have to give your camera a hand.
There are settings on your camera that can be set to regulate the amount of light entering the lens of your camera. This will be your shutter speed. Not enough light will mean underexposed or dark photos, and too much light will mean overexposure.
Focus
When shooting photos, you also have to think about focus. Your eyes automatically focus on the object you are viewing. Some cameras come with auto focus, but this is not a perfect feature. Your camera will focus on the center of the frame, which is not always where it needs to focus. Manual focus is much more precise and adjustable.
Mechanics
As you point your camera to take a shot, you must consider all of the information above. Once you have compensated for light conditions, adjusted the focus, and framed your shot, all you have to do is press the shutter button and the camera will do the rest.
The shutter button opens the shutter and allows light coming through the lens to be exposed to the film in the camera. The image is recorded onto the film and the shutter then closes.
The film is essentially a thin layer of plastic coated with special light sensitive chemicals. Once a frame of film is exposed for a photo, the film should be advanced to the next frame for the next shot. The film should not be exposed to any light in between shooting the photos and developing, or they photos will be lost.
Final Thoughts
While this is a very basic explanation, it gives a beginner enough information to get started. The more you experiment with your camera, the better you will understand how it works. If you are really serious about photography, your local college may offer classes, which will greatly expand on these basics.