How do I light a large group of people in low light (inside a temple)?

Question

I shoot Bar/Bat Mitzvahs inside a temple with extremely high ceilings and poor lighting throughout. Many of the shots at the beginning of the day are of family with large numbers of people.

There are large steps not too far off from where people stand, so placement of a light source is often difficult. I'm typically on a ladder shooting fairly straight on to the group of people at the bottom of the steps as there isn't enough room for me. Lighting is difficult.

Using only one flash produces ok results directly in camera, but I use pretty high ISO to get the results. I'm adding a second light but trying to decide where I should be using a light modifier such as an umbrella, and what size, or to just go bare flash. I've read a bunch on the subject, but the fact is that my group size will be large and I'll most likely need to place the flash at a distance (maybe 10') from the group to get the results.

Should I get a large 60″ or 70″ umbrella and use it as a reflective (as it seems like that will spread more light) or should I go bare flash? I'm also considering buying Canon's triggers and have the possibility of two off-camera flashes, but I know this can add to difficulties as I am trying to get a lot of different types of shots in a short amount of time and I don't want to have to keep adjusting the placement of the lights and constantly finding my settings.

Using one flash on camera has been a blessing in that I can keep things moving. I know it won't be ideal no matter what, but a good starter set up that isn't too much of a headache will be a good start.

Answer 1

Ideally, you'd want two lights on stands, with umbrellas to soften the light. Each light should be pointed toward the opposite end of the group at as close to a 45-degree angle as possible. This distributes the light across the group more evenly.

Here's a quick-and-dirty diagram to illustrate:

Answer 2

I did this a few times, it is a lot of work in post, but works great with low budget and no assistance.

Camera in tripod, small aperture, low iso, remote trigger for ambient/background, no people around.

After that, people aligne and form, I adjust focus and aperture if needed. Then I proceeded to walk in font of the group, left to right, holding a medium size softbox in a boom. Big succession of shots (automatic and remote) to find best expression for each person (and lighting).