Next Question is:
When Hensel talks about a 1200 watt second pack and head combo... Is the the "true" or "effective" power.
AB1600 is 1600 w/s, but the TRUE POWER is really 640 watt seconds.
When these big boys like elinchrom, profoto, and Hensel say 1200 w/s or 2400 w/s, do they really mean 1200 or 2400 TRUE w/s?
AFAIK Alien Bees is the only company that quotes "effective w/s" (which is the 1600 number in an AB1600). Everyone else uses "true" w/s, which is directly derived from the size (uF) of the capacitor(s) and the voltage stored.

