Help with Elinchrom quadra ranger..

I know the power variable runs in 1/10 steps over 6.6 f-stop range. If the wattage is at 2.0 what would that be aperture wise?

It's difficult to say really, would depend on several factors such as light distance to subject etc. Do you have a specific scenario in mind?

For instance if I had no light meter and wanted to get it spot on nearly first time without using the histogram.
Say I was using one light at 45 degrees, one foot away from the model with a shoot through umbrella 33".
I've always used a light meter so I've never really taken much notice of how many stops it accounts for. So I was seeing what each step in the wattage roughly stood for.

Nobody would really know, nor could anyone tell you. It depends on your camera, your ISO, the umbrella brand and reflectivity, and what other reflective surfaces are close to your model. Only you could find out for sure.

BTW, if you are looking for low power, 2.0 is not the lowest power setting. 0.4 is, but you have to plug into port B to get down that low.

Good point, I was seeing what roughly people estimated it at. I was seeing what everyones views where.
In my head I've always said 2.0 is 4 full F stops higher so if i had to shoot at f/1.4 with the kit it would be f/5.6 using shoot through umbrella with the distance being around 1 foot. Then after the f/5.6 each full watt is a full stop higher, so 3.0 would be f/8, 4.0 f/11, 5.0 f/16, and 6.0 f/22.

I know this was wrong thats why I was asking, but I guess it is impossible

The real point of it is to give you a way to match elinchrom lights. If your BXRI, quadra, and ranger all have f/4 on the readout, they are all putting out the exact same amount of light, even if they are radically different maximum power units (800, 400, 100, etc).

It really has no correlation to the camera or lens.

Poopinmymouth, What a name lol.
Now I'm confused... The only difference to the units would be the last stop I take it?
So if it was 800 watt unit that could be dropped to 100, the 400 dropped to 100 also and the 100 is running at max power they would all produce the same light?
If I was using a 800 watt and full power and the 400 watt at full power the 800 watt would be the Key light with the 400 watt being the fill light with a ratio of 2:1 or would it work differently?

No, the point is you ignore the wattage, and pay attention to the F stop number. The 100 watt unit won't go above a certain number, but as long as you can get all of them to read the same number, it will be identical output.

So theoretically a 100 watt might only go up to f/6 (I don't know the actual number) but a 200 watt to f/8, etc, but as long as you have the 200 and the 100 both reading f/4 on the panel, you know they are pumping out the same amount of light.

but even then, this is all made useless by other settings. Even if you have them both reading f/4, if they are at different distances, or have different lighting modifiers, it changes things up as well.

Thanks thats cleared up alot so you can't really tell till you pull out the light meter yourself and figure it out in each situation I suppose. My mind is bubbling.
I've know I've gone off the subject now but say I brought Elinchrom Style RX 300 instead of the Style RX 600w. The only difference between the two would be the Style RX 600 could push one full stop higher?

Yep, that's correct