Talk about being late for the party. I wish I could put my 2 cent in before your trip to the Antelope Canyon. Anyway, in case someone else decide to go there, here is my 2 cent worth. I was at the Upper Antelope Canyon, this June for the light shafts. This year, they have a guide for the photographers, which is 2 hours. It is just for the photographers, the guide take you in and show you where the light shaft going to be at what time and which is the best area to take pictures. They did not have this, last year, they just let you roam around for 2 hours. I have been there on 06,07 and 08, to shoot the light shafts.
The Upper Antelope Canyon is a walk in type of Canyon, you really do not need a guide, I never had one, the Indians that is in charge, controlled the people, so that you could take pictures, without people in your pictures. The times I was there, I never had any wind, blowing sand down the canyon, when it does, it is really bad for the cameras.
The Lower Antelope Canyon is across the road from the Upper, in fact it is in the same river bed but own by different Indian family. The photographer paid his rate and they let you go for 4 hours, it is below the surface of the land. It is below ground and I was there a day after my trip to the Upper Antelope Canyon, I did not get any light shaft, it was too open at the top and too much light comes in. It was not windy so, you can not see any shafts, no sand was blowing into the canyon. I was also there, last year in October and the lighting seems better, because no hot spots.
What I know now, it is best to go to the Upper Antelope Canyon, in June and shoot the light shafts, then go to the Lower Antelope Canyon and shoot there. As long as no sand is blowing around.