How does the light meter on a Vivitar 3800N camera work?

The light meter lets you set either the shutter speed or the aperature. When you look in the view finder you'll see either a red positive or red negative sign. This means there is either too much light or not enough light based upon the cameras settings. If you want to control the shutter speed set it where you want it to be. The aperature setting is the variable setting that you move until you see a green dot in the view finder. When a green dot is found in the view finder you have the correct settings. If you can't get a green light by adjusting the aperture setting then the shutter speed is too fast for the lighting conditions. In this case move the shutter speed to a slower setting then adjust the aperture ring again. It's all about the lighting with this camera. If you do not see a green light in the view finder you do not have adquate light to expose the film properly. By the way, you should not hold a camera in your hand with a shutter speed of one sixtieth of a second or less. The picture will blur from motion. This is much easier to show than explain. I . I am a Photography teacher at a local high school and we use the 3800N camera.