If you’re already tiring of wedding season, this isn’t going to make you feel any better. Sebastian Staacks has out-gifted us all. No serving spoon sets or gift vouchers here. For his cousin’s wedding he made a bullet time photo booth using an array of DSLR cameras triggered by Raspberry Pi Picos.
What does bullet time mean?
Bullet time photo booths comprise multiple cameras rigged together. Each camera takes a photograph at the same moment simultaneously or with a small delay between them. Software then joins each of the photographs to create a video with the striking “bullet time” effect. The effect is best known for — and indeed named after — its use in this bit of The Matrix in which people’s prince Keanu Reeves dodges bullets with an impressive backbend.
You might also have heard of it as frozen moment, dead time, flow motion, or time slice video.
A three-Pico wedding
Twelve cameras are attached to a curved rig that looks a bit like a ballet barre. Look at the image below and you’ll notice the cameras are placed at greater distances apart towards the wall on the left, and much closer together on the other end. This achieves the impression of the action accelerating when the shots are played back in sequence.
A Raspberry Pi Pico acts as the camera trigger. It has to make sure all the camera shutters go simultaneously in order for the bullet time effect to work. Two further Raspberry Pi Pico Ws sit inside Bluetooth wireless buttons so the wedding guests can control the action. The green button starts the countdown to a recording and saves it, and the red button can cancel a countdown, or trash it if everyone looks idiotic.
DaVinci Resolve software created the final video of all the shots stitched together. Its Optical Flow Estimation generated artificial additional frames, and allowed sections to be blurred or slowed down to making the stitching look more fluid.
Details, details, details
Sebastian created an incredibly detailed project page delving into each element of the build, from the camera triggers to building the rig and post-processing the images. His GitHub repo is also a treasure trove of all the code you’ll need to build your own and become the most popular wedding guest ever. Well, maybe next wedding season.
