PHOTO OF LONGEST EXPOSURE OF EIGHT YEARS REVEALED

The Closing Ceremony of the 2012 Summer Olympics in London took place in August 2012. A week after the athletes parted ways, an MA student started a project at the University of Hertfordshire in the UK. Regina Valkenborg created a camera obscura out of an aluminium beer can, adhesive tape and light-sensitive photographic paper.

A sky-facing camera on the wall of  Bayfordbury University Observatory was forgotten - it withstood the elements for eight years and a month. David Campbell, the observatory's chief technology officer, finally took down the camera this fall. In it, he discovered the longest-exposure image ever taken, showing the sun's paths across the sky for eight years.

During his time as a fine arts student, Valkenborg became interested in using ancient technologies to capture images. She started to experiment with a pinhole camera using a technique known as camera obscura.

A small hole in a light-tight box lets in the light from the outside. The image of the outside world is flipped and projected into a darkened room. Early photographers learned to capture this optical phenomenon by placing light-sensitive film behind a small hole, as Valkenborg did. While many camera obscura require exposures of seconds or more, a beer can camera called Days in the Sun's eight-year exposure is the longest on record.

What may be the longest exposure photograph in history was taken at Bayfordbury Observatory over 8 years - using a pinhole camera made from a drinks can. https://t.co/25QSIoYmBt

— University of Hertfordshire Observatory (@BayfordburyObs) December 10, 2020

During the eight years that the camera was attached to the observatory, the photographic paper inside recorded what is called a sun plot, showing the sun's arc across the sky. The highest arc is the summer solstice; the lowest, the winter solstice. Some days didn't make a great impression on paper, probably due to cloudy weather. No people or trees pass by, just the bright light of the sun. According to a statement from the university, the paper recorded a total of 2,953 sun trails.

Valkenborg's camera was never meant to be eight years old. Fortunately, the mobile observatory returned to the same orientation each day. According to the observatory, the camera recorded the view from there for a  time equivalent to 4% of the entire history of photography. In the process, the camera went down in history for its unlikely (and unplanned) survival. While Valkenborg's exposure of the sun is believed to be the longest known exposure of the image, other photographers experimenting with pinhole cameras are hoping to set new records.

In 2015, Jonathon Keats placed his 1,000-year-old Millennium cameras to watch  Lake Tahoe for what seemed like an impossible eternity. For many, the appeal and challenge of pinhole cameras and long-exposure photography lies in capturing a changing world in constant motion.