I get the focus to the eyes as with some old series and movies like star trek original, but with M4 without knowing the intent it is all guesswork. Maybe intensity?
Here's an interesting take on it.
There are an infinite variety of ways you can combine the basic types of camera angles, with each one having a different effect on how the viewer will experience the photograph.
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Narrow View Angles - aka, Close-ups (field of view)
The narrow view or close-up shot is almost always a subjective type of camera angle. You’re getting right in there, up close and personal, noticing all the subtle details, colors, and textures. You’re identifying and even feeling one with the subject, whether it’s a person, plant, animal, or any kind of object.
In cinematography of human subjects, it’s called the “reaction shot” because the close-up helps the viewer intimately experience the emotions and state of mind of the person in reaction to the situation at hand. The close-up works well in revealing the personality of subjects, or the essence of some aspect of who they are as a person.
Variations of the close-up include the head-and-shoulders shot, the head only shot, and the “choker” that zooms in to an area starting below the lips extending up just above the eyes. Photographers also use other types of close-ups that cut in to different areas of the face, although a fully effective reaction shot usually requires the inclusion of the eyes and mouth, which are the most powerful facial features of human emotional communication.
The close-up works so well in bringing a subject to life that it can animate even inanimate objects by allowing us to closely experience it’s features and sensations. Imagine, for example, a close-up shot of water gushing from a faucet, or a piston pumping in an engine.
Extreme close-ups enter the territory of macro-photography, where we might feel that we are merging with, losing ourselves in, or becoming engulfed by the subject, sometimes in a spiritual or mystical manner, as in the close up shot of the plant. We might become so deeply immersed into it that we even lose sight of what the subject is, as in some forms of abstract photography. The identity of the subject itself is no longer the objective of the photograph, but rather the intricate colors, patterns, tones, and textures that comprise the subject.