Most film buffs are familiar with a range of stylistic techniques employed by directors to tell a story—camera angles, shot length, set design, and special effects are all used to help create the unique look and feel of a film. But there’s one technique that’s often taken for granted or ignored by audiences—aspect ratio. 

Aspect ratios aren’t an on-screen device. Rather, they determine the dimensions of the movie itself—whether the image is widescreen, square, or IMAX, for instance. In the past, most directors would employ a standard aspect ratio (4:3), but nowadays, filmmakers often play around with different ratios, using them as a thematic device. 

In this short video essay, Now You See It explains exactly how filmmakers employ different aspect ratios. The video moves quickly and covers a lot of territory, from epic action movies like The Dark Knight Rises and Star Wars to indie films and romantic comedies like The Grand Budapest Hotel and 500 Days of Summer. The video is fun and educational—and it might just change the way you think about movies.