ECU is the standard abbreviation for Extreme Close-Up, a shot framing that shows an isolated detail of a subject at very close range, such as just the eyes, a portion of the face, a specific object feature, or a small but significant element within a scene. It is the tightest framing in the cinematographer's toolkit, used to create maximum visual emphasis and emotional intensity.

Extreme close-ups eliminate all context and focus the viewer's attention entirely on a single detail, often revealing texture, expression, or information that would be invisible at wider framings. In emotional scenes, an extreme close-up on the eyes can convey subtle shifts in feeling with extraordinary power. In suspense or thriller filmmaking, an extreme close-up on a mechanism, weapon, or object can create tension by suggesting its importance to the unfolding action. The framing is so tight that even minor movements become magnified, making every twitch, blink, or shift in expression significant.

In AI image and video generation, specifying an extreme close-up or ECU helps models understand that the output should be tightly cropped on a specific detail rather than showing a broader view. This instruction is particularly effective when combined with descriptive detail about what element should be isolated and what emotional or narrative function the tight framing serves.