Sometimes, long shots can actually correspond to the distance between the audience and the screen for a sense of reality. If you are sitting in the tenth row center, the objects on the screen are at the actual distance and size they would be from that seat to the screen. Action scenes, gun fights, martial arts, fighting aliens mano y mano usually takes place during a full shot to bring you close to and into the action, making you feel like a participant. Yes, there can be action in a long shot, but in long shots, you are observers not participants. Again, it s the director s call, depending on what emotions he wants you to experience.
Emphasis is now on character interaction.
And you are privy to a private conversation of usually not more than three characters. Conversations rarely take place with a character s back to the audience, unless the director wants to deliberately keep you out of the conversation. To get a fourth character into frame, the camera needs to pull back, becoming a full shot, too distant for a private conversation. Watch closely the next film or television show and you ll notice that most, if not all, dialogue takes place at a medium shot to let you into the circle. Close-up means drama.