An interesting use of ‘Fill Flash’
I was wandering around a friends farm yesterday and we went in to see what was in the old barn. It was quite dark inside – a bit too dark for taking many pictures but on the way out I thought that I would try a picture of the outside framed by 
the inside barn door. I had the camera set to manual and adjusted the settings for the light outside. I then switched on the flash to light the interior. Without some light on the interior the surrounding part of the inside of the barn would have been completely dark. The flash gave a comparable light balance to the outside light. This can be adjusted on most cameras so that you get a little more or a little less flash.
One could use a tripod and set the camera to get the available interior light but the result of that would be an overexposed outside. For me this was a great balance. And a very simple way to get the lighting balance that I wanted.
