#2. "RE: D5000 and SB-900 - can it be done wirelessly or not?" In response to In response to 0
Welcome to Nikonians! As Chris wrote, You have to set the SB-900 in SU-4 mode, The built in Speedlight in Manual flash mode, and the camera in Manual exposure mode. With the SU-800 in the cameras hotshoe and the SB-900 in remote TTL mode, you will be able to take advantage of full i-TTL wireless falsh control in P,S,A, and M exposure modes. Good Luck and Enjoy your Nikons!