My opinion, your current D2 battery can laaaaaast you a long time....so get the battery for the flash then after that the D2 batt. But if you got lotsa of $$$ just buy BOTH.
My opinion, your current D2 battery can laaaaaast you a long time....so get the battery for the flash then after that the D2 batt. But if you got lotsa of $$$ just buy BOTH.