2) Usually, when the key light is placed directly behind the subject, the effect is rather unflattering. The subject's face is cast in shadow, and only the top portion of their hair is highlighted. While usually not suitable for normal portraits, this type of lighting would be excellent for portraying "evil" or "malevolent" characters, because of the deep shadows and lack of highlights. Unless, of course, the lighting is so bright that only the silhouette of the subject is rendered.
3) If the light is positioned directly in front of the subject, the subject's face is fully illuminated. Usually, this type of lighting lends a youthful, happy, or excited mood to the photograph as a whole, because unflattering shadows beneath the subjects' eyes or around their mouths are eliminated. As a result, most professional portrait photographs choose to employ the full-face lighting technique.
4) Adjusting the light stand height so it stands above the subject's head is another useful technique for commercial portrait photographers. To be sure, there are more shadowed areas than with the light positioned directly in front of the subject; however the subject's faces do not appear as flat. Furthermore, part of the subject's face can be cast in soft shadow, albeit not as dramatically as with moving the light right or left.
5) Granted, if the light stand height is adjusted so that is below the subject's chin, then the subjects' face is illuminated in a ghostly fashion. Similar to young children who hold flashlights beneath their chins to appear monstrous, this particular lighting technique yields dramatic highlights on the subject's forehead, cheek, mouth, nose, and chin. In the absence of shadows, the subject's face appears pale and washed out. This technique is probably best utilized for cinematic lighting; such as with models posing for movie posters.
