If the group photo consists of people at varying distances from the camera, such as rows of people sitting in bleachers or standing on risers, you could end up leaving some faces out of focus, which is a significant problem. Try shooting with the smallest aperture you can use (large f-stop number) to give you the largest depth of field (which is the segment of the photograph from front to back that is in focus). Unfortunately, using a small aperture allows less light to travel through the lens, which can make shooting a group photo indoors a challenge. However, if you move farther back from the group, you can shoot with a smaller f-stop number/larger aperture and still achieve a useable photo, such as f/4, by using infinity focus. Just be sure to use a camera with the largest image sensor you can find to make this technique work as well as possible. Additionally, be sure to set the focal point in the middle of the group (in terms of depth), rather than at the front or back, to ensure the entire group is focused accurately.