In order to compare Einstein power to Canon 430 EX and 420 Ez flash out, I have made the following test
1. I setup my light meter at 10 feet away on light stand with ISO 100, shutter speed 1/250, measured using non-cord method so that no ambient light will affect meter reading.
2. Flash and Einstein are fired through reflective umbrella using cactus V5.
3. Einstein full power (640 W/s) = F/11+6/10 ~ F/14
4. Canon 430 Ez (full power@80 mm) = F/2.8+7/10 ~f/3.5
5. Canon 430 Ex (full power@24 mm) = f/4.0 +4/10~f/4.5
6. So Einstein at full power equal to, to double power f/4.5 to f/6.3 ( 2-430Ex),to triple power f/9(4-430ex),4 times power-f/13(8-430 Ex) and 4+1/3 power - ~5 flash, so 13 430 Ex = 1 Einstein