I was shooting a catalog cover in the woods. It was for a leather company which made gun cases, holsters and accessories. I was using an 8x10 camera on a heavy tripod. While hiking to the location, I bashed the rear of the camera against a rock, breaking the ground glass into several pieces, which made composing and focusing impossible. I gathered up the largest of the glass pieces and after arriving at the proper spot, I threw the dark cloth over the camera and proceeded to set up the shot by holding a piece of the ground glass in various places in the focusing frame. I lucked out and got the shot!
By the way, the ad agency guy who set up the stuff was hiding behind a rock. We didn't think to bring a walkie-talkie (pre-cell phone era) and had to communicate using hand gestures since we couldn't hear each other over the rushing water.
Bucheimer by
artist21227, on Flickr