I have a Canon 430EXII, GN 43/141, ISO 100 and an Andooer560 IV, GN 50, ISO 100. Is there a way to figure out the necessary power on the Andooer for fill flash, without trial & error? For example, say I want to set the Andooer (fill) to 1/16 of the current power of the Canon (main). Hit & miss (my main MO) works, but is time consuming. With both at 1/1 and 1/1, the Andooer seems a fair bit brighter.