The more people you have in the photo, the smaller they appear, and the harder it is to see the individual faces. Ideally, you want to fill the camera frame with people both vertically and horizontally, and this is achieved with thoughtful positioning of the subjects. By doing this you can get closer to them and they appear larger and easier to see in the photos.
The first thing in any group is to have people stand at a 45-degree angle to the lens, rather than shoulder-to-shoulder facing the camera. This does several things. It allows you to get your subjects closer together, they appear slimmer, and it’s more professional-looking. And don’t have them all facing the same way unless they’re a ’60s Motown group. Better to have them turned toward center on both sides.
Small groups of three to eight can be taken standing together to produce a pleasing picture. They will fill the camera frame from top to bottom and side to side nicely.
Left to pose for a picture without direction from the photographer, a large group of subjects will usually stand shoulder to shoulder in a long line. This produces a photo with small people and excess space at the top and bottom of the frame.
Any group larger than eight or so should be positioned in levels, either by having some people in front sitting on chairs, or in back standing on steps. I like to have somewhere around 35-40% of the group in chairs and the rest standing behind, as this fills the frame better than an equal number of seated and standing subjects. Alternatively, you can have the first row standing in front and the second row on a step behind. Try to keep your rows close together, and try to position them so the people in the back row are standing between the two people in front of them, not directly behind them and hidden from camera view. A good way to check this is to ask each subject in back to make sure that they can see the camera with both eyes, thus ensuring that you’re not photographing just part of their head.
For a group of around 25, a good posing scheme would be some people on chairs, some standing behind, and some seated on the ground in front. Alternatively, you can have a second row standing on a step a level above those standing behind the chairs. The point is to fill the picture both side to side AND top to bottom.
The larger the group becomes, the more imperative it is that you find stairs to put your subjects on. Estimate how many rows you have to make in order to fill the frame top to bottom and side to side. The best approach is to have the subjects line up according to height. Start the bottom row with the shorter people, and end the top row with the tallest. This keeps a taller person from blocking a shorter one behind them. Subjects seated in bleachers or stadium-style seating is also very popular in schools and sporting venues, and can produce good results. You can follow the same principle as positioning on stairs.
If stairs or bleachers are not available, you have another option: setting the camera at an elevation above the crowd and shooting from above. This can be accomplished by using a ladder to get slightly above a small group, or a rooftop or balcony for a large group. Everyone can just look up, but you may still have to position people so taller subjects are to the rear of the shot.
Having someone to assist the photographer in positioning larger groups is extremely valuable. Only from dead-on camera position, that is, looking through the viewfinder, can you judge whether a face in the crowd will be fully visible or partly or totally blocked. Having an assistant position subjects while the photographer looks through the camera saves a lot of time and footwork.
The easy way to light is to just have everyone looking toward the sun, but the results can be disappointing. Your subjects will be squinting, they will have shadows under their eyes, and if it is hot they will be uncomfortable. The preferred method is to have the subjects’ backs to the sun, and to use flash to illuminate them. For a small single-row group, you can use your camera mounted flash. Multiple row groups will need a flash mounted on a camera bracket or light stand. This is to prevent shadows being thrown onto the people standing in the back rows. Large groups will need multiple flash units on tall stands. You can trigger them with remote receivers from your camera-mounted transmitter. Three flash units work well, one on the left, one on the right, and one next to the camera. And make sure they are high enough so they don’t produce shadows on the faces in the back rows.
You’ll also need a good lens hood to block the sunlight from hitting the lens and producing a flare. If the sun is low or you’re shooting directly into the sun, you may also need to position something above the camera to block the sunlight, and throw a shadow on the camera lens. This can be done with something as simple as a piece of cardboard or a magazine, or even an umbrella. There are also professional devices you can buy.