The fill flash
responding to a question by Ulrich v. P. who asks how to use a flash during daylight and avoiding a dark background while creating a way too light foreground:
It is advisable to use the flash when you are shooting against the sun. You might need to fiddle with its strength, but once you’ve got it right, your so called fill flash will brighten up the foreground and makes sure the background does not overexpose.
Using a diffusor for a softer flash makes the light less harsh.
In the picture below, I did exactly that. Without the flash, their faces would have been dark (underexposed) or the background blown out (overexposed). By fighting the sunlight, you can balance and find the point in between.
This all has to do with the lower dynamic range that the camera has compared to the eye. Especially digital cameras, which can only cover an even smaller range and not everything from dark to light.
Oh, and by the way: If you use a sun bouncer to reflect the sunlight, you might not need the flash. See examples here in this series of mine.



