Bullet Time vs Chroma Key
バレットタイム / クロマキー
Both sit in Film Technology, so the question is not what they belong to but how they behave. Both are read here as technique. They are reached for with some of the same intent, which is where they get confused.
Bullet Time
An arc of still cameras fired at once or in sequence: time nearly stops while the viewpoint alone moves. The Matrix popularized the idea of the virtual camera.
Chroma Key
.jpg)
Compositing that renders one color transparent so the image can be laid over another. From optical blue-screen work through the BBC's CSO to today's green screens and virtual studios, it has remained the foundation of the craft.
| Bullet Time | Chroma Key | |
|---|---|---|
| Era | 1999– | 1930s– |
| Family | Film Technology | Film Technology |
| Kind | Technique | Technique |
| Cues | Frozen time / A traveling viewpoint / The arc of cameras / Live action mixed with interpolation | A single-color backdrop / Keyed edges / A separated foreground / Lighting designed for the composite |
| Best used for | Circling a decisive instant in a fight or a sports play · Freezing a new product and moving only the viewpoint around all of it | Weather and news, putting a presenter and graphics into one frame · Adding places or scale after the shoot when the real thing is impossible |
| Type | Fix the type in space and let the camera arc distort it | Choose lettering colors far from the key color and from the plate |
| Composition | Subject at the center of the arc, a straight reference line behind it | Fix eyeline and horizon height for both plates before shooting |
| Material | Even lighting keeps shadows from jumping and hides interpolation errors | Light the backdrop evenly and pull the subject away to stop spill |
| Caution | This is not slow motion spectacle. The core is separating time from viewpoint, and repeating the freeze and orbit at moments that are not the peak of the story drains it. | Compositing without matching the light, leaving green on the edges while shadows fall in a direction the background never had. |