Add a Gelled Flash
When you move your subject to reduce the number of light sources, you may have moved her into a poor lighting situation. Back at the record store, suppose you determine the ideal location of the model and the dominant source of light is tungsten. Yet this light is still quite unflattering, even after setting a good white balance. Because the room features overhead tungsten lights, you decide to add a flash to the scene to improve the direction of the light on the subject.
Fundamentally, you follow the same steps as you learned in Chapter 3: Set your white balance for the tungsten scene using a gray card or an ExpoDisc, then add a flash with a matching tungsten gel, sometimes called a CTO or color temperature orange gel. (Tungsten light is orange.) Notice the difference in the image before (Figure 4.6) and after adding the flash (Figures 4.7 and 4.8). The flash adds contrast and a better direction of light to the image.
Figure 4.6. Here the tungsten- illuminated model has very unpleasant light on her face. There are shadows in her eyes, and she seems to blend into the background.
Figure 4.7. When you introduce a flash into the equation, the subject pops from the background and has a better quality of light on the face. With no gel, however, the light on her face is a different color temperature (daylight) compared to the ambient light (tungsten).
Figure 4.8. Add a tungsten (CTO) gel to the flash so that the flash color temperature matches the ambient light. Not only does the flash improve the quality of light on the face, but now you can neutralize the white balance for a balanced image.
If you do not gel the flash in this scene, you will be creating your own mixed-light scenario. While the scene is tungsten, your flash is daylight balanced. If you leave your flash ungelled, then you will have a tungsten environment with daylight flash on the face and body.