A laser-like beam of sunlight reaches 130' below the ground to the floor of Upper Antelope Canyon. I highly recommend a wide angle zoom lens when shooting at this popular location. There is a lot of sand blowing into this slot canyon (and the 4 other slot canyons I was in during this trip), so any lens changing should be done inside a protective bag. A towel or other protection for the camera and lens would also be a good idea.