Skin tone, surface and backdrop
Skin tone and surface
Most heads offer several skin tones. Heads with their own painted skin can also switch between Neutral Sculpt and Realistic. Neutral Sculpt hides the skin detail so light and shadow are easier to read; Realistic shows the head’s own skin. While Realistic is on, the skin-tone buttons are disabled.
Skin tone and surface change how strong the contrast and color feel, even when the lights stay the same. Pick the one that fits what you want to judge.
Backdrop
Backdrop sets the background from dark to light, which helps you judge separation and contrast around the subject. It is a visual background only: light does not bounce off it the way it would off a real paper roll or wall.