I have volunteered to take photos at the Last Chance Stampede & Fair here in town. I will be taking photos for the Equine Exhibit and some of the displays. Come to find out the Equine event will be indoors. If it is a sunny day and the doors are open there should be enough light. I could really use some tips on the best settings to use for an indoor arena. My equipment consists of a Canon 60D, 28-135mm lens, a 70-300mm USM lens and a nifty fifty. I don't own a off camera flash at this time. Which lens would you use for this event? What I've found so far is to open up my aperture as far as possible, then increase the ISO if necessary to get a fast shutter speed. When I volunteered I didn't realize the event would be indoors and I don't want to back out now. Please help me get some good photos for these people.