The area we visit for Day of the Dead is one of the few places in Mexico where this cultural event is still celebrated in this very traditional fashion, so the locals are quite accustomed to the thousands of tourists (national and international) that flock here to see it. We do, however, recommend that you are respectful and avoid stepping on graves, and only take close-up photos of people after requesting permission. Your guide will remind you of this on the tour.
Please note, this event is a celebration, and for most of the people at the cemeteries, it is celebrated with family, often involving music, alcohol and food.