I recently had the assignment of photographing all of the doctors in an oral surgery practice in one group shot. They wanted a skyline of Austin in the background but they wanted the emphasis to be on the doctors. The skyline should not compete. We scheduled a late afternoon shoot at the Long Center which is just across the Lady Bird Lake from downtown proper.
I set up the shot so that the doctors were in open shade (the shade cast by a building or natural object but in which the sky is open above...). It was a beautiful day and the sunset was great. The scene behind the doctors is the view to the east. I used one big light to bring up the exposure on the doctors to match the ambient lighting.
I brought an Elinchrom Ranger AS RX pack and put all the power into one head, modified with a 42 inch Varistar umbrella box. I put the box as far back as I could in order to get an even spread of light all the way across the group. I also tried to stay away from using a wide angle lens to prevent the heads of the people on the ends of the group from being distorted.
The shot was done with a Canon 5Dmk2. Lost to the web is the amazing amount of detail in the image. The client's marketing team blew the image up to four by six feet and it was pretty impressive. One doctor shoed up in bright track shoes but we were able to retouch them into dress shoes.
Groups can be difficult. Open shade and powerful flashes are always your friend.