The use of a reflector is intended to bounce light back on to the face, but with less light intensity as the originating light source. The bounced light does not totally flatten the face and make the facial features ‘disappear’ because all the shadows are not totally removed.
The use of a strong light source in line with the camera lens straight square on to the face would remove the changes in light and dark caused by the relief shape of the face and produce a very flat featureless face.
In these series of photographs I have used natural and artificial available light in these portraits with and without the use of a reflector. The camera settings remained the same for all these photographs to demonstrate the difference a reflector makes. Camera Nikon D3100, 40mm focal length lens, ISO-200, F-Stop f/5.6, I/60 second exposure.
The bottom row of photographs the faces have dark shadows on one side of the face, the facial features such as the nose and cheeks, chin and necks cause some of the face to be thrown in darkness because the light source is strong from one side. The faces have dark eyes caused by a lack of light thrown directly on to the face.
The top row of photographs I have used reflectors with the assistance of a helper to hold the reflector in position. I used a silver, gold or white reflector placed in positions to bounce some of natural light back on to the face. The intention is to throw light back on to the face or neck depending where the reflector is positioned. The reflected light is to reduce the shadows, to brighten the area around the recessed eyes, but to still keep some light and shade on the face so the facial characteristics and features and are still defined by the light shadow.
The reflector held low pointed back up to the face, to remove shadows under the chin.
If the reflector is held at approximately the head height the bounced light removes the strong shadows and highlights that can occur when a reflector is not used.
The light of the colour bounced of the reflectors changed depending on the reflector used. Silver and white reflectors gave bright reflection. The gold reflector gave a warm colour hue to the face portrait. The white and silver reflectors give a colder light similar to the ambient quality of light colour.