Allow enough time for all of the photographic permutations required. For a small bridal party with two attendants on each side, an hour and a half is usually enough. For a medium bridal party, allow two hours. If your party is large, with more than six bridesmaids, plan on three hours for photos. The more people in a photo, the longer it takes to set up, and the more frames the photographer needs to shoot to get one where everyone looks good. If you have a small bridal party but a large family, add more time for portraits. Your photographer will also advise you on how much time to budget.
On the schedule you give the attendants, give them a call time thirty minutes before they’ve actually needed. That way, if some of them are late, they won’t hold everyone up.