camera
Stereoscopic (3D) stop-motion capture
Capture technique / Miniature cinematography
Definition
Shooting a stop-motion frame twice from two known, fixed-offset camera positions -- one per eye -- so the finished film carries real, in-camera stereoscopic depth rather than a post-production conversion. Pioneered as a full-feature method on Coraline (2009) and scaled to a multi-rig production pipeline on ParaNorman (2012).
Overview
Stereoscopic stop-motion capture photographs two distinct frames per exposure -- one for each eye, offset by a fixed horizontal distance -- so the finished film carries real, physically-recorded depth rather than a post-production 2D-to-3D conversion. Because a stop-motion frame is already a single static exposure rather than one frame of continuous footage, the production can take the extra time each frame needs to capture a second, offset exposure without changing the fundamental shooting method -- the same puppet, set and lighting simply gets photographed twice, from two known camera positions, before the animator moves anything for the next frame.
LAIKA's Coraline (2009, catalogued here as coraline) was the first feature conceived and shot this way from the start. Cinematographer Pete Kozachik's department supplied a horizontal camera slider that let the crew set an exact left-eye and right-eye position for every frame; as Dragonframe's own account of the production puts it, "we borrowed a horizontal camera slider from Pete Kozachik that would allow us to set a left and right position for each frame," with the software's motion calculator handling the dolly maths between the two positions. A single camera, physically repositioned twice per frame, kept the two eyes optically identical -- same lens, same sensor, same exposure -- at the cost of doubling the number of exposures needed for every frame of the film.
LAIKA's ParaNorman (2012, catalogued here as paranorman) scaled the same principle to full production volume rather than changing the underlying method: the show fielded 63 Canon 5D Mark II bodies, each rigged with left/right sliders for stereo pairs, backed by 53 motion-control systems (36 Kuper units and 17 proprietary rigs) and 21 additional motion-control track-and-boom setups, ultimately generating 1,770,601 individual frames across just over 20 hours of finished footage. Running dozens of dedicated slider-equipped camera bodies in parallel, rather than one camera serving the whole shoot, is what let a feature-length stop-motion production sustain stereo capture across every set on the schedule at once, rather than one camera cycling through positions for a single unit.
Both productions still needed a conventional 2D compositing pipeline behind the stereo capture -- Coraline's stereo image sequences were prepared in After Effects (see after-effects-compositing) before the digital 3D projection pass -- so stereo capture adds a camera-department and scheduling problem on top of, not instead of, the rest of the stop-motion pipeline.
Workflow
- Set a fixed horizontal camera offset (the interaxial distance) appropriate to the miniature's scale, matched to a slider or a second camera body positioned at that exact offset.
- Expose the frame from the left-eye position, keeping lens, focus and exposure identical to what the right-eye exposure will use.
- Reposition to the right-eye position -- either sliding the same camera along its rig, as on Coraline, or triggering a second, paired camera body, as on ParaNorman's multi-rig setup -- and expose the same frame again.
- Repeat for every frame of the shot before the animator moves the puppet for the next frame, so both eyes see the identical pose.
- Conform and grade the left- and right-eye sequences together in post (e.g. After Effects) ahead of digital 3D projection.