Professionals use a number of terms to describe the space around their subjects. Understanding and using these concepts is important, since the proper use of space is a key to good composition.
The example on the left clearly has too much headroom; the shot above has “just right” headroom.
"Headroom" is the term given to the space above the subject's head. On television and in films, there is a consistent sliver of space in close-ups of people. Too much headroom makes the shot look off-balance—and too little cuts of the subject's head.