I see that the unit can be dialed down to 75 watts/second -- that’s a HUGE difference (from 2400 watts/second). I'm not sure how to do this.
1) With one head: First separate the channels (A/B instead of A+B). That means that there are now 1200 w-s in each of the channels.
2) Using the rocker switches for the channel you now switch from full to 1/4 power, Full pie to 1/4 pie symbols, 1200>600>300
3) Now use the variator to reduce up to another 2 stops in 1/3rd stop increments: 300>150 (-1) > 75 (-2) watt-seconds.
To get up to another full stop of reduced energy if you have two heads, use the B channel (which has two head connections), and connect both heads. This gets each head down to 38 (I'm rounding) watt-seconds. If you only need one light point the second one into a box or a closet.
If you need to reduce light more than that a black scrim, Neutral density gels or additional layers of diffusion are useful just make sure you have plenty of air circulation around the lamp head. Light modifier choice can also make a big difference in light output.
If you need to reduce power more than that and want to stick with Profoto, either an Acute 2R 1200 or D1 monolight are good options. Outside of the Profoto ecosytem I recommend the Paul C. Buff Einstein 640 Monolight which has excellent light characteristics (consistency and very short flash duration and there is an equally large (but different*) range of light modifiers available and can be reduced down to about 2.5~3 watt-seconds.
* Every light manufacturer makes a few light modifiers that no other manufacturer makes. You will also find certain people who say you absolutely have to get Brand B1, B2,B3,D,E,H,N,P,S to get X quality of light - and while that is true as far as it goes you will need to test for yourself to see what works best for you.
