I'm trying to capture video from a Nikon D90 DSLR in either default video library or GSVideo.  I have the camera plugged in via USB, but Capture.list() can't find any capture devices, and the equivalent function in GSVideo returns the error: IllegalArgumentException: Element does not implement interface. Is there something I am forgetting to set on the camera itself?  Can't seem to figure out.  Meanwhile a typical external USB webcam works fine.