2.8) Lighting and Luminosity: 97 Reinventing The Tattoo App :

Whether your light source is visible in the tattoo or not, it’s critical that your light rays all appear to converge on one point. The easiest way to be sure of this is to choose a point somewhere that will be your light source (this can be inside your composition or at the far end of your drawing table) and then use a ruler to make sure every ray follows through in that direction. Rays that aim in random directions will look sloppy and unrealistic (The one exception: Underwater scenes, since water can refract light in unpredictable ways).

The direction and color of a light source can do a lot to establish the mood and psychological space of a piece, and lighting from below has a particularly potent energy to it. Our eyesight evolved in a natural situation where almost all light came from above. Because of this, light from below can produce a mood that is nocturnal or otherworldly, and this can be a very potent graphic tool.

Although it goes against common sense, dark colors are often important in showing the brightness of a light source because light colors appear lighter when contrasted by darker colors. The organic branch that passes in front of the glowing pod here not only helps establish the light source but also gives the composition more strength and flow.

On-Camera vs. Off-Camera Light Sources In this chapter, most of the light sources are visible as glowing objects in the composition; these can be referred to as on-camera light sources. Others tattoos, such as the one on the following page in Fig. 98a, show the effect of the light without showing the actual light source; these can be referred to as off-camera light sources. In both cases, the origin and effect of the light must be considered while shading the piece, but an on-camera light source can bring an added sense of illumination to a design (along with additional design challenges). Typically, light sources are kept off-camera in most tattoo designs; only in particular cases is the light source desired as a visible compositional element.