Structured Light 3D Scanner (SLS) Cameras
A structured light 3D scanner projects a known pattern of light in front of the sensor, then measures the distortion of that pattern when viewed by a detector. This allows a software program to create a virtual map of the objects in front of it. It is most accurate when the scanner remains stationary and the object is stable, though advanced systems can track real-time motion. It is relatively simple for computer vision software to recognize human-shaped objects within this depth data, especially when they are moving. Motion-controlled video games use this data to identify where people are in front of the sensor and overlay a digital skeleton or avatar based on the people in the room.
Paranormal investigators will turn up the tracking sensitivity of these SLS cameras and look for human-shaped anomalies on the theory that they are disembodied entities. Militant debunkers will say they are just a trick of the light or software artifacts, and point out that these devices were never designed to work that way. The truth — as always — lies somewhere in between. While it is true that SLS cameras were not designed to capture ghosts or spirits, hardly anything is. And when a device is created expressly for that purpose, debunkers will say that there is no evidence that it works. You can't win for losing. Using SLS to detect entities is no different from using an audio recorder to find EVPs. It is a tool that has uses beyond what it was originally created for. That doesn't preclude its use in investigating the paranormal.
The biggest problems with an SLS camera are its expense and lack of portability. Currently, a dedicated portable computer or tablet is needed to analyze the depth data and run the tracking software. Combined with the infrared emitter, sensor, and external power source, the overall cost builds up quickly. Even if you already have those hardware components lying around, you still need specialized middleware to drive the system. A complete, turnkey field solution can easily cost several hundred dollars. This high price point places it out of reach for part-time paranormal hobbyists, leaving it generally as an option only for those with financial backing from an entertainment channel or independent wealth.
Probably the most salient reason for using an SLS camera is the "coolness" factor, especially for paranormal entertainment shows. It looks remarkable to see stick figures appear out of nowhere. Because these systems are often handheld, the constant movement shifts the infrared matrix across the environment. This causes the software to misinterpret static objects, making the stick figures jitter and move around constantly. It is fascinating to watch, particularly when investigators ask an entity to wave and the stick figure appears to comply.
Ultimately, the SLS camera proves that in modern ghost hunting, the line between technology and illusion is incredibly thin. Whether those jittery stick figures are genuine manifestations or just an algorithm frantically trying to find human shapes in empty corners, they make for unforgettable moments. Watching a faceless, handless line-figure raise a blunt arm to wave back at you in the dark is a chilling experience — even if it is just a glitch in the machine.
