When most people think about making a time-lapse video, they imagine a camera set on a tripod, snapping photos at regular intervals.
But what if you could create the same effect just by taking out your phone and capturing a picture whenever you pass the same spot—no tripod or fancy setup required?
A research team at Cornell University has created software that makes this possible. Called Pocket Time-Lapse, it lets anyone with a smartphone camera capture subtle changes in a scene over days, months, or even years, then turn those photos into a smooth panoramic time-lapse video.
The idea began in 2020, when Abe Davis, a computer science professor at Cornell’s Ann S. Bowers College of Computing and Information Science, was starting his new job during the pandemic.
Lockdowns made it hard to set up a traditional lab, so he began experimenting outdoors, taking pictures of places he passed every day—his apartment window, a bus stop, and the construction site of a new university building. Over time, he collected more than 50,000 images.
Working with then-undergraduate Eric Chen (now a PhD student at MIT), along with other collaborators, Davis developed new techniques to align and organize thousands of photos taken from slightly different angles, at different times, and in different weather conditions.
This was no small challenge—unlike standard time-lapse projects, the pictures weren’t taken from exactly the same position or lighting each time.
The team’s breakthrough was figuring out how to “connect the dots” between photos that weren’t taken in sequence. For example, they could match a sunny midday shot to a night photo by using a twilight picture from another day as a bridge. This allowed them to weave together a consistent, seamless video from thousands of separate images.
They also introduced a method called “time splatting”, which factors in the position of the sun, GPS data, and local weather conditions for each photo. This makes it possible to adjust the look of the video—changing shadows, shifting the time of day, or even transforming daylight into nighttime in the final sequence.
The possibilities for Pocket Time-Lapse go far beyond casual photography. It could be used to monitor construction projects, track environmental changes, observe seasonal shifts, or even support medical and scientific fieldwork.
Davis says it also offers a fresh way to appreciate familiar surroundings.
“This tool gives you a different way to look at the world,” he explained. “Most of my photos came from places I see every day, but the time-lapse revealed details I’d never noticed before. It’s like opening a new window into your own environment.”
Pocket Time-Lapse will be presented at the Association for Computing Machinery’s SIGGRAPH 2025 conference in Vancouver this August.
The team hopes that soon, anyone with a phone in their pocket will be able to capture the beauty of change over time—one everyday snapshot at a time.
