Been reading a lot on balancing ambient light and flash. Saturday night had perfect opportunity to practice but results weren't what I expected. Here's one of the photos. See how dark the background is. Wasn't actually that dark in the place. Is there any easy-to-understand method. I'm shooting Digital Rebel and Canon 583EX. I understand betting the ambient reading and maybe stopping down 1/2 to 1 stop, but should that ambient reading be on the main subject or background? Lost here. Help me find my way. Here's one of the pics in my failed attempt.