An installation of real grass at Wimbledon: three tennis players (well, two tennis players and a long-time groundsman) photographed in a process that takes place during a week spent in a darkened room.
In discovering more about this process, I came across a wonderful blog:
Check out inhabitat.com here
The artistic team of Ackroyd and Harvey projected black and white images for 12 hours at a time onto grass panels, which absorbed light and responded by producing chlorophyll to different degrees. A bit like when I leave the hose out on the lawn for a couple days.