I use one umbrella with lamp of 150W viseversa from the model and one lateral light source of 100W through diffuser. Nothing more, no strobes no nothing more...... but I se on the forum shutter speed 1/125s with only one lateral light source and black background......
I can get a proper exposure with 1/4s or 1/8s and model beeing very still, but what would I do if I have to shoot a model in jump for motion photos????
Thanks for reading and reply-ing
Zak, I'm going out on a limb and say that you're probably using two standard issue house lamps of 100W and 150W. That's not enough light to shoot quality images at the shutter speeds you desire. Most of the guys you read about who shoot with one light against a black background are using a much more powerful strobe light.
You can either buy a set of strobe lights, or add a few more powerful house loghts ... or ... if you have a flash head that attaches to the top of your camera -- take the flash off your camera and connect it with a sync cord, then fire it into your umbrella. I started out with three oldl flash heads, a sync cord and a couple of wireless optical slaves -- and got great images!