Antelope canyon is located near Page, Arizona. The upper canyon is about 1/4 mile long, about 60 feet tall and varies in width between about 4 feet and about 20 feet. It is fairly dark, requiring timed exposures of 1 or more minutes in order to capture the subtle colors and plays of light bouncing down through the narrow slit at the top.
Completed Images (click thumbnail to expand)
Uncorrected Proofs (click thumbnail to expand)
Other Notes and Information:
The low light conditions, depth of field requirements, and the filter factor of an 85B (if using Tungsten balanced film) all combine to result in exposures times which typically exceed 1 minute. This would not be a problem if it were not for the tourist groups that come through, snapping away with their instamatic cameras with automatic flashes. Of course, with a flash exposure, all they will capture is the redish brown rock. They won't capture the luminance of the light itself and they won't capture the rainbow of colors created by the light as it bounces its way down the slot canyon walls. But their flashes will ruin any timed exposures. So, after setting up and opening the shutter for a multi-minute exposure, I usually end up running around franctically to make sure people don't fire a flash until the exposure is complete.
Due to long exposure times required, reciprocity failure is an issue. The shift in exposure time is not the main problem. What is necessary to avoid is any color shifts that could cause the loss of the subtle colors created by the cascading light. I have found that using a Tungsten balanced film, with its inherent suitability to longer exposures, and an 85B filter to correct for daylight works best.