Static setup, no movement — focal length and framing locked for the entire take. No pan, tilt, or zoom. Standard for dialogue, VFX comps, and repeatable takes.
The camera is stationary, the tripod is locked, the focal length is set — you can't get more secure than that. A locked-off camera eliminates the sources of error that arise with dolly or pan movements. You mount it on a sturdy tripod, set the focus, choose the focal length, and then you don't touch anything else. During the shot, absolutely nothing happens to the lens or the tripod head. This is the core of this working method.
In practice, you need this technique constantly. In dialogue scenes, the actors turn, speak, move around the room — but the camera stays where it is. You work with multiple locked-off cameras to cover different angles: one on the main character, one on the person they're talking to, perhaps a wide shot of the entire location. Later in the edit, you assemble the shots, and this static framing gives you precise, repeatable compositions. No shake, no zoom drift, no misunderstandings with the focus puller about movement speeds.
For VFX work, the locked-off camera is indispensable. When the motion capture department or the compositing suite needs green screens and tracking markers, the camera must be absolutely stable. Movements in the image space are created by the actors, not by the lens. This greatly simplifies the reconstruction of the 3D camera position in virtual space. Especially with greenscreen work, when you add downstream environments, a locked-off perspective is worth its weight in gold.
The signature of this method is visible — sometimes intentionally. Feature films use locked-off cameras to suggest objectivity or to create formal, statuesque compositions. Documentaries and interviews use it because the setup is faster and the attention is drawn to the speaker, not the camera. In the low-budget realm, it's the standard method — one camera on a tripod, two or three focal lengths, done.
The disadvantage is that you can't make adjustments during the shot. If an actor stands further to the right than expected, it's too late. So, you need clear marks on the floor, precise agreements, and a monitor on which you study the composition before shooting begins. With digital cameras, this has become easier — you have real-time visual references on the video assistant monitor, not just in the eyepiece.