The art of lighting differs on highlights and shadows as well as the way light effect is given. In shot - 1, below (see fig.19) the contrast between highlights and shadows, a key feature to low key lighting. On the contrary, In shot - 2, under high key lighting, the subject is under no influence of high contrast range between highlights and shadows.

Shot - 1: Low key Lighting

Shot - 2: High Key Lighting

Fig.19: Highlights and Shadows - Low and High Key Lighting.

The background light is effectively used to highlight clothes and clothing accessories in the background of the stage scene as we can see in shot - 1 (see fig.20) below.

In shot - 2, the kicker light, placed behind and below the subject unlike rim light, placed behind but above the subject, creates an “hallow effect”. Such techniques are often employed in shampoo commercials.

Shot - 1: Background Light  

Shot - 2: Kicker Light

Fig.20: Use of background light and Kicker Light.

Similar to background light, set lights are used to provide sufficient baselight in the scene to avoid video noise and to flatly illuminate all relevant portions of the set.

Fig.21: Typical use of Set Light.