Conceptual artist Jonathon Keats holds up one of his "Century Cameras" ahead of the opening of his ambitious project. John Macdougall / Agence France-presse

Photographs capture fleeting moments in time, but what would be revealed if an image could show an entire century?

That is the question behind the latest "thought experiment" by the American conceptual artist Jonathon Keats, whose past endeavors include a bid to genetically engineer God, and porn films for houseplants-complete with close-ups of bees pollinating flowers.

Using ultra-long-exposure cameras, he has set out to document Berlin's shifting urban landscape over the next 100 years.

The 42-year-old, based between San Francisco and northern Italy, invited people from this week to take one of 100 small pinhole cameras and place it in a strategic Berlin location.

To add to the fun, he's asked them to keep mum about where they have hidden their "photographic time capsule", only revealing its location in their old age, to a child who could in turn wait until adulthood to retrieve it.

Keats is promising that whoever returns a camera 100 years from now to his partners in the project, Berlin-based Team Titanic gallery, will see their photo go on display and get their 10-euro ($14) deposit back.

A date for the CenturyCamera exhibition's opening is already in the diary - May 16, 2114.

"I will not be in attendance," the artist says, dryly, in an interview for the project launch.

But he doesn't mind at all.

The self-styled experimental philosopher wants to probe how "putting a camera in the hands of the unborn "can make people scrutinize the legacy of the decision taken today for their city.

"The first people to see these photos will be children who haven't yet been conceived," Keats says.