One light is enough to learn direction.
Lighting patterns describe the shadows visible on a face. They are not universal coordinates on the studio floor. The same stand position can make a different pattern when the subject turns their head, the modifier changes size or the light moves in height. Start with an arrangement, then read the photograph.
Use one flash and switch off other flashes. If you add a white reflector, it is still a one-flash setup, but it contributes fill. Record its position because it changes the result. A dark surface near the shadow side can reduce reflected fill; it cannot subtract light from paths it does not block.
Four starting arrangements.
Soft, near-axis light
Place the source close to the camera direction and slightly above eye level. Keep it out of the frame. Look for open shadows and useful catchlights; excessive height can deepen eye sockets.
Loop light
Move the source to one side until the nose casts a small downward shadow that remains separate from the cheek shadow. Refine height and head angle rather than relying on a fixed degree value.
Rembrandt-inspired light
Continue turning the light or face until the nose shadow joins the cheek shadow, leaving a lit patch below the eye on the shadow side. Facial structure and modifier size affect whether this pattern appears.
Split light
Move the source toward the side of the subject. Inspect where the division crosses the face. A close, large source wraps differently from a small distant source.
Shape first. Exposure second.
Light position and apparent source size control much of the visible shadow behavior. Changing power mainly changes brightness. If the nose shadow is wrong, increasing output will not move it. If the shape works but the meter reads too low, adjust output or another exposure variable deliberately.
Moving a modifier closer changes distance, apparent size, coverage and falloff together. Use the source-size coach to understand the size relationship, then re-meter. A grid can help manage spill, but it does not make a large modifier behave identically to a small bare source.
YOUR NEXT 10 MINUTES
Predict. Measure. Refine.
Which direction should the nose shadow move when the light moves sideways?
Keep the subject’s head still. Make three frames: near the camera axis, a little to the side, then farther to the side. Match exposure after each move.
Compare nose shadow, cheek shadow, catchlights and the transition into shadow. Do not judge only overall brightness.
Choose the frame that supports your subject and intended mood. Use the recipe builder to save a starting plan and your measured refinement.