It is cooler in the canyon than outside. Dark in places lighter in other spots. Shutter times was from 5 sec to 88 seconds long. Other than being crowded it is really beautiful. This is from the upper canyon the lower one is narrow on the bottom and wider at the top, but there is lots of ladder climbing in that one. I will try it out later this year (I hope) Grand time, Loved Bryce and Zion National parks..