You expose for the sky then you set up some off camera flashes to expose the person properly.
Can you or someone else explain how to do this.....
Set your camera to spot metering, and aim your center focus point at the sky.
Adjust your ISO to the lowest setting (depending on the time of day) and center the light meter in the viewfinder. If you're going to use flash to light your subject, chances are you will only want to go up to 1/200s shutter speed. You can stop your aperture down if the sky is too bright at 1/200s, ISO 100. Then, you light your subject with off camera flash.