Since I'm constantly looking for inspiration, I tend to run across many "different" artists, and Abelardo is no exception. He's taken the Camera Obscura "Pin Hole" technique to a whole new level. Mr Morrell has done a series of photographs in where he rents a hotel room in the down town area of a big city, then blacks out the windows, and make a small hole in the black out fabric/paper, basically creating a room-sized pin hole camera. He then sets up his medium format camera under the hole he created facing back into the room and opens the shutter. He'll leave his shutter open for hours, slowly collecting the light that trickles in through the hole and exposing an image that is invisible to the human eye. His results can be seen here:
http://www.abelardomorell.net/camera_obscura1.html