The first is a full-face view. This is produced when the model is facing directly into the camera. In this pose, both ears are visible. A full-face pose is good when you want to show the symmetry of a model’s face, or when you want to convey an assertive attitude.
In a full-face view, you see both of the subject’s ears. This view works well for a shot where you want to show symmetry.
When the model’s face is turned slightly away from the camera, the far ear disappears. This is a three-quarter view of the face. This pose is good for revealing the shape and contours of the face. It is also more demure and less assertive than a full-face view. Normally, it is recommended that the face not be turned so far that the nose extends past the line of the cheek. In a full-face view, you see both of the subject’s ears. This view works well for a shot where you want to show symmetry.
A three-quarter view is good for showing the contours of the face.
When the face is turned at a 90-degree angle to the camera, the pose is called a profile. In this pose, only one side of the face is visible. This is a classic type of portrait that exudes grace and abiding beauty.
Profiles reflect a quiet and simple beauty that is timeless.
*excerpted from the book Posing Techniques for Photographing Model Portfolios