Below is a short summary and detailed review of this video written by FutureFactual:
2 Billion Frames Per Second Light Camera: See Light Move and See the Past
Overview
A creator builds and improves an ultra-high-speed camera that records light at up to 2 billion frames per second. The setup uses a single pixel sensor, a motorized mirror, a laser, and a minimal optics train to capture discrete light events. By tiling many one-pixel videos from different directions, it reconstructs a true ultra-fast sequence and demonstrates unusual light travel effects and perceptual delays.
What’s New
Upgrades include a belt-driven, encoder-enabled mirror for higher pointing precision, a more sensitive detection chain using a photomultiplier tube, a refined data path to the oscilloscope for synchronization, and mechanical torque limiters to protect the motion stage. The result is clearer, HD-quality imagery at unprecedented frame rates and new ways to explore how light moves in time.
Overview
The video presents an upgraded, ludicrously fast camera designed to capture light at two billion frames per second. Unlike conventional video, this system records one pixel at a time and builds a complete image by rapidly sampling many directions. It demonstrates that light travels at the same speed in all frames of reference, yet perception of that speed changes when the camera itself moves, leading to visually striking effects.
Hardware Architecture
The camera uses a single pixel sensor based on a photomultiplier tube (PMT) to detect single-photon events, fed into a high-bandwidth oscilloscope. Light is directed through a long focal length lens to a pinhole that sets the pixel size, with a motorized mirror steering the light path in different directions. A key upgrade is the use of a belt-driven yaw/pitch stage with encoders, providing high angular resolution and repeatability. A 12-bit encoder partitions motion into thousands of directions, enabling HD-like sampling without requiring a massive array of sensors.
Electronics and Synchronization
A central challenge is synchronizing ultra-fast photodetection with data capture. The PMT signal is read by the oscilloscope at 2 gigasamples per second, with a clever two-way cable setup that allows triggering and data acquisition to occur on the same channel. A separate synchronization signal is conveyed to the scope to align frames after capture, producing a coherent 2D image from many independent pixel recordings. The result is a timing diagram in which events separated by nanoseconds are stitched into a single, temporally resolved image.
Light and Perception
The presenter explains that regular cameras average over light paths, while the ultra-fast system reveals path-length differences that create apparent speed variations. By repositioning the camera, light traveling along longer versus shorter paths can appear slower or faster, illustrating the relativity of simultaneity in a tangible demonstration. The video also references Ole Romer’s historic measurement of light speed, now visualized at human scales in a garage setting.