What is Open Gate?
It's a technical term that describes how the full, uncropped area of the image sensor or film frame is used during shooting.
The Literal Meaning: Using the Full Frame
- What the "Gate" is: The "gate" is the aperture through which the light passes to expose the film strip inside a film camera. It's the physical opening that defines the size and shape of the exposed image.
- What "Open Gate" means: When a camera is shooting "open gate," it means the camera is recording the entire usable surface of the film or the full image sensor area, including the space that is normally masked off (cropped) for the final projected aspect ratio (like 16:9, 2.39:1, etc.).
Why Shoot Open Gate?
Filmmakers and cinematographers choose to shoot open gate for several important reasons:
| Reason | Explanation |
|---|---|
| Maximum Image Information | It captures the most detail and the largest resolution possible from the sensor or film. This gives maximum quality for visual effects, color grading, and archival. |
| "Future Proofing" | Since the final aspect ratio is not yet chosen, the filmmakers have the flexibility to decide on the final crop later in post-production. They can experiment with different aspect ratios (e.g., cropping a wider image for a film festival vs. a taller image for an IMAX release). |
| Reframing/Repositioning | It allows the editor or visual effects (VFX) team to shift the frame up, down, left, or right in post-production to subtly re-center the subject, stabilize the image, or adjust compositions without losing image quality. |
| VFX Plate | VFX artists prefer open gate footage because the extra surrounding image area (called "padding") provides more data to work with when tracking, compositing, or scaling visual effects. |
Contrast with Normal Shooting
In a normal film production workflow, the camera often has a ground glass or electronic mask that shows the cinematographer the intended final cropped aspect ratio.
- Normal Shooting: The camera is set to only record the area intended for the final output (e.g., a 2.39:1 frame).
- Open Gate Shooting: The camera records everything, including the areas outside that 2.39:1 frame.
Summary
"Open gate" is a film production technique where the camera's full sensor or film area is exposed to maximize image quality, resolution, and creative flexibility in post-production.**