The best thing to do is try it and see what happens. You my want to head to your local camera store and see if they have a cable that will hook up between your SB400 and the camera flash shoe. You will still have most of the camera control but won't have to spend a bunch on a new flash. I have done this quite a few times as my "goofing off" camera kit is a D7000, A 18-200 VR zoom, an SB400, the cable and a few needed accessories. It all goes in a small bag and doesn't kill my shoulder after a long day.