Portrait lighting definitions

Fill light- may be used to reduce the contrast of a scene to match the dynamic range of the recording media and record the same amount of detail typically seen by eye in average lighting and considered normal. will make shadows seem lighter or darker than normal which will cause the viewer to react differently by inferring both environmental and mood clues from the tone of the shadows. any source of illumination that lightens areas of shadow created by other lights. lighten shadows created by the main light.
Main light- primary and usually the strongest light. responsible for providing shape and form.

Hair light- a light that is used to light up the hair. can cause lens flare.
Background light- controls how light or dark the background behind the subject is.
Shadowless lighting- use of soft light. can reduce shadows without creating additional shadows. large light source, close to the subject.
Butterfly- created by the way in which you angle the light to fall on the face of your subject. butterfly shaped shadow under the nose.
Loop- made by creating a small shadow of the subject noses on their cheeks. shadow of the nose and the cheek do not touch.
Split- splits the face into equal halves with one side being in the light and the other in the shadow.
Rembrandt- identified by the triangle of light on the cheek. shadow of the nose and the cheek do meet and creates a triangle of light in the middle.
Grey Card- a middle gray reference, typically used together with a reflective light meter as a way to produce consistent image exposure and or color.
Hard light versus soft light- Soft light refers to light that tends to "wrap" around objects, casting diffuse shadows with soft edges. Soft light is when a light source is large relative to the subject, hard light is when the light source is small relative to the subject. Hard light sources cast shadows whose appearance of the shadow depends on the lighting
Strength - shutter speed and aperture's appropriate to portraits.- low aperture to blur the background so that the attention is drawn to the subject. wide aperture- shallow depth of field. use a shutter speed that is higher than effective focal length.
instrument3:1 lighting ratio- A 3:1 lighting ratio occurs when the light discrepancy between two light sources is one and a half f-stops
Inverse square law of light (remember photography)-The inverse-square law for light intensity states: The intensity of illumination is proportional to the  inverse square of the distance from the light source. the power of the light will be inversely proportional to the square of the distance.

the posing app.
chin out and down
position subject sideways
turn the shoulders
using a wall- to look natural
relaxed hands