burkphoto Loc: High Point, NC

I've done this before, when teaching school photographers how to handle similar situations. Set up well ahead of time, so safety and performance can be assured! Liability issues abound here.

Use ONLY grounded (3-wire/3-prong plug) extension cords, and be absolutely sure they are plugged into GFCI outlets. Seal any in-line connections with electrical tape.

Put cones and safety barriers up to block people from coming near your lights. Use gaffer tape or duct tape to secure all wires.

Trigger your lights with a wireless remote if you have one, to avoid taut sync cords from tipping a light stand into the pool. If you must use a wired sync cord connection, have plenty of cord, and tie the middle of it to something secure — between you and the lamp head.

Indoors at 30 to 42 feet (three rows), you will NOT need all the light from your flashes. But I would still use the 1600 w/s monolights in umbrellas. I'd probably use at least 60-inch umbrellas. Get them up as high as possible, using extremely sturdy 10–14 foot stands. Set them at 1/3 intervals of the group width, and aim each at the far side.

Using a flash meter, check the light across the target area for uniformity (+/- 1/3 f/stop) and adjust as needed. Remember, the higher you can get the lights, the less you need to worry about shadows from the front rows obscuring people on the back rows.

On an APS-C or DX camera, with a 35mm lens focused at about 34 ft. (second row), at f/6.3, everything from 24 to 60 feet will be in focus. You DO NOT need to stop down much farther than that! In fact, doing so will reduce overall sharpness, while not giving you any more *useful* depth of field. You may need a wider lens, but I'd try to use as long a focal length as possible, to reduce distortion of folks at the edge of the frame.

Remember to compose for a crop that will keep everyone in the size prints you are providing. If you do a lot of this sort of work, go to www.viewfindermasks.com/‎ and learn about viewfinder masks for "machine printing" composition.

You may find that three rows of 13–14 people make a bit wide of a composition, with lots of wasted space above and below. If the water is dark enough to act as a field for titling, you can overlay digital names of the swimmers in the foreground. If you need to fill a 10x8 composition, try composing five rows, with seven to nine per row.

With care, sufficient lighting fixture height, and safety, you can pull this off. If the front row sits on the edge of the pool (legs not in the water!), the middle row kneels, and the back row stands, you should have a decent composition.

Rick from NY Loc: Sarasota FL

My advice? Buy low and sell high.

wlgoode Loc: Globe, AZ

Pour some flash on it, that will freeze the group.

canon Lee

I am using Canon 580ex flash, which is triggered by the camera flash. I have misplaced the sync cord and don't have an adapter to activate my radios. This leaves me with using 2 580's and triggering it with the camera flash, which I am certain wont have any effect on the shot. Thank you for your advice.

canon Lee

Bingo!! that's the ticket, just the added incentive to use my flash. Thanks for reminding me about something I knew but forgot.

burkphoto Loc: High Point, NC

Your two 580s might make it that far... But perhaps not in umbrellas... You can probably rely on ISO 400 to 640 if needed, to get to a medium aperture.

One more thing I forgot — use a shutter speed of 1/60 second maximum time, up to your camera's minimum sync speed. I like 1/125 or 1/160 if the camera supports it. You can get a brighter background with slower speeds (longer times), but that risks subject movement after the flash, along with impure white balance from the mix of flash and ambient sources.

RWR Loc: La Mesa, CA

Actually you mentioned your two flash units in your post, which is why I recommended you check your ISO 800 guide number. What is your minimum aperture at 30 feet?

Reinaldokool Loc: San Rafael, CA

They sell ground fault circuit interrupters for extensions cords. They will provide an extra measure of safety--in case. They are used extensively on construction sites. You are going to need all the diffuse light you can get.

Doug B Loc: Edmonton Alberta

I have done shoots in pools before though not that many. I have also seen camera crews at our pool with cables running all over. Most pools have sufficient light for a shoot. I would suggest that if you are doing this to have a second person to watch your equipment and to keep your shooting area clear while you are working.