The ultimate in large format camera obscura

"The Great Picture, as the group calls it, will measure 25 feet by 100 feet. The hangar that will become their camera obscura is 160 feet long and 60 feet high, and the photographers will hang the cloth at a focal length of 80 feet from the pinhole, Burchfield says.

Incidentally, "pinhole" is an imprecise word; the hole will probably need to be a quarter-inch or more in diameter. Burchfield says the team is conducting experiments with different aperture sizes and exposure times.

Most likely, the photo will need to be exposed for five to 12 days, Burchfield says, depending on the results of their experiments.