People walking through Bristol will have their shadows recorded and played back for others to interact with as part of a new public art installation.
Technology fitted into street lights will capture people as they walk underneath then play back an image of the person for other passers-by to see.
The commission, called Shadowing, by Jonathan Chomko and Matthew Rosier, has won the Playable City Award which aims to use technology to connect people.
It will run for six weeks.
It is all about "surprise" said designers Mr Chomko and Mr Rosier, who are both based in Italy.
"Our goal is to create unexpected interactions between people who share an urban environment."
The precise location of the installations is being kept secret so people can discover them for themselves, but all are in pedestrianised areas.
A map pointing to general areas where they can be found will be published on the website for the Watershed, which is behind the Playable City Award.
Each installation can make a maximum of 14 recordings before the shadows are overwritten.
If nobody passes by for a time, the street light goes into a "dream state" which triggers the installation to play a history of shadows for people to watch.
"I'm excited to see what people do when no-one is watching," Mr Chomko said.
"If you walk home the same way each evening, I want to see how you communicate with the shadows over time."
Mr Rosier said the pair hoped to create "a momentary awareness of other Bristolians who share that same space".
After the Bristol launch at the Making the City Playable Conference, Shadowing will be taken on tour internationally.
Watershed's first Playable City commission last year was Hello Lamp Post.
That project enabled people to "talk" to the city's street furniture by sending text messages which would elicit a response from lampposts, postboxes, bollards, manholes, or telegraph poles.