I love photographing and being creative with high key and I came across this advice which you might find helpful also.

But first I hear you asking “what is high key“?

High Key is generally a picture that consists almost entirely of light tones with relatively few mid-tones or shadows. There are varying definitions for high key which can pretty much confuse most people. So to keep it simple, any image that has deliberate overexposed areas either in the subject or background is pretty much High Key (of course you can end up with high key by accident but here we are talking about deliberate).

The question was …

“Hi, Please I need help with this studio setup. I need to photograph children(between 6 and 11 years old).
The client wants the background completely white (high key), and the children well illuminated. They are little models of children’s clothes. “

And the response by Steve.Korn from Flickr.com ….

“Usually, a 4:1 ratio is what many will say, but with digital, there is an easier way to do it without frying the background.

Before the kids arrive, set up your background lights and do a few test shots. Shooting at your desired ISO and aperture, set the background light levels so that they are just hot enough to clip the right side of your histogram. This will ensure that the background is a pure white but not bionically bright.

Be sure your kids are not too close to the background or the background lights will spill or make a glowing halo around them. If you can get them 8-10 feet in front of it, you’ll have no problems. A little closer and you’ll be fine, but if you can err on the side of more distance it will ensure you are safe.

Next, turn off your background lights and meter just your key and fill lights.

When the kids arrive, turn everything on and you will be good to go.

Have fun and good luck with the shoot. “