>Thanks, Marty! Ultimately if I do go this route I'll >probably get the SU-800 but if I point the speedlight upward >maybe it won't contribute as much to the exposure. I was >blocking the output from the on-camera flash, when using it as >a Commander. > Hi Anne,
In commander mode on the SB-800 you can set the main flash to "--" which means it will not light the subject itself:
"The “Commander function” in Advanced Wireless Lighting enables the SB-800 to act as a commander unit during wireless multiple flash shooting to trigger remote flash units without firing itself. To activate the “Commander function,” set the SB-800 as the master flash unit and set its flash mode to “Flash canceled (---)”. This operation will normally not affect the correct exposure of the subject, although the exposure might be affected if the subject is close and a high ISO sensitivity has been set. To limit this effect as much as possible, bounce the light by tilting or rotating the SB-800’s flash head."