It is rather difficult to use a SB-910 with a D700 in CH (5fps)mode. The recycle rate of the SB-910 is 2.3 to 4.5 sec. What you need is to use constant light source. If the SB-910 were able to fire at the 5fps rate, it would reduce power to prevent over heating (a SB-900 would melt). I imagine others will comment on ways of doing what you want. High speed flash photography is not an interest of mine.