Never Never buy an SB-900. They are prone to overheat problems during heavy usage. Right after they were released and the overheat problem surfaced they had a software patch that was supposed to fix it. Did not work. Four months later the SB-910 was rushed out and the overheat problem was resolved. I have two SB-900s and I am stuck with two that over heat constantly. If you want to spend a lot buy the SB-910 but I would steer you to buying a used SB-800 on ebay. SB-800 was a super flash!