An HDR image of Upper Antelope Canyon, Page, Arizona. Antelope Canyon is the most-visited and most-photographed slot canyon in the Southwestern United States. It was formed by erosion of Navajo Sandstone, primarily due to flash flooding and secondarily due to other sub-aerial processes. Photography within the canyons is difficult due to the wide exposure range (often 10 EV or more) made by light reflecting off the canyon walls.Photo credit: Luca Galuzzi