I am on a tight budget. What's the best type of back light to use for portraits, especially black backgrounds? I want to make my subject "pop" away from the background a little more....especially dark haired people. Also if you can recommend any other lighting options for indoor portraits let me know. I am working with an SB600 with a flash trigger. I also sometimes have issues with my flash on black backgrounds. I can set up my umbrella on a white background and it snaps away with no hesitation. When I try it on the black background it doesn't. It blurs and doesn't like to click fast. Should I be setting my camera up different? Working on a Nikon D5000.