Quite a wide range of shots can be called ‘medium’. Typically they cover people from ‘three-quarter length (knee) shots’ to ‘mid’ shots. The productional value of a medium shot lies somewhere between that of longer shots in which the surroundings predominate, and closer shots in which the viewer concentrates on the subject and ignores whatever else is nearby. Medium shots allow the audience to see both the performer/talent and their surroundings clearly.
In a medium shot, you can still keep quite large gestures, arm and body movements within the frame. When the subject moves around a little, there is usually no need to re-focus or to re-frame the shot
Depth of field is sufficient at typical working lens apertures (e.g. around f/5.6) for you to keep the subject sharply focused, while leaving the background details slightly softened. As you tighten the shot, the surroundings become less distinct and lose their impact – so the subject itself becomes more prominent, and isolated from its surroundings.
With medium shots you can move the camera around smoothly on shot (using a normal to wide lens angle). You can adjust camera height unobtrusively, particularly if camera movements are motivated by action in the scene; e.g. someone getting up and going over to open a door.
For the director, the medium shot provides a safe, uncritical, general-purpose viewpoint. It offers the audience a useful amount of detailed information and so can sustain interest for a relatively long time.
While long shots give your audience the opportunity to glance around a scene freely, eventually they will want to take a closer look at whatever catches their attention.
A close shot restricts how much the viewer can see, and so concentrates the attention. But it normally only holds interest for a comparatively short period.
Medium shots
Theses have various important features. They enable the viewer to see a reasonable amount of detail in the subject, while at the same time revealing its surroundings. So the environment, lighting etc. make a strong impact. Medium shots can contain a considerable amount of action without requiring adjustment of the camera’s position.