The three-point studio lighting setup allows you to light your subject from three different sources: the main light, the fill light and the back light. Effectively using the three-point lighting setup helps control the shadows, balance the contrast and create different moods for your image.
Review how each light affects the subject differently:
The main light, also referred to as the key light, is the primary light source, and it is the brightest. The main light will establish exposure, and its placement is essential to create different lighting techniques. The main light is most often placed in front of your subject at an angle. Changing the angle of the light can influence the mood of your photographs and the emotional character of your subject.
The fill light is used to “fill in” or lighten any shadows produced by the main light. It is often placed in front of your subject, opposite the main light. The fill light is used to lighten shadows and to create contrast between the subject and the background. This creates a sense of depth.
The back light is used to outline the subject against a background. Aim it at the subject from behind, but not in a position that would be directed towards the camera, causing a lens flare. Adjusting the position of the camera can help you avoid this.