This picture was made not in the studio.
In fact I made this picture in the forest .
And wasn't dark . It was bright sunny morning .
I tell you how I did it.
On the branches of the trees I hang black piece of fabric as a background .
I choose place in the shade. So I have less sun as possible.
I want it to eliminate strong ambient light.
I use one speed light with 60x60 soft box.
Remember soft box works best when is placed closest as you can to your subject (model in this case)
Position of the light is also important .
I kept standard 45/ 45 degrees.
When you using speed lights , your camera should be set to manual mode.
I set shutter speed 1/200 of the sec.
That was maximum flash sync. With my camera.
iso lowest I could which was 100.
Remember I want it to minimize sun light.
My aperture was set to f/8
Remember, closing aperture will reduce amount of light reaching your sensor.
If the number f/ 6-8-14 is higher !
Less light reaches your sensor and the pictures will be darker .
Same with speed . Faster it goes less light come in.
And of course ISO lower it is , less light comes in.
Don't be afraid to try . Try all different settings .
Trying is fun . And when you get to good result, that really satisfying.
Speed light i set to manual mode not Ttl . I want it to be in full control over my camera and light.
Power of the light was set to 1/32 . But before final picture I was trying with all kind of power setting .
With lowest and with highest .
Till I reach the light I want it.