I am trying to get an image such as: https://500px.com/photo/103497551/-by-brett-walker?from=editors&only=Black+and+White
My setup is a SB700 speedlight, D7000, and a tripod.
When I try this, I cannot get the light to stay localized and way too much of the subject and background is illuminated. Also, the light seems way too strong and not soft as in this example.
Is a proper setup all that is needed or do I need additional gear, too?
An easy setup is to sit the subject in a dark room facing a doorway. Crack the door open to let in a shaft of light. Or use a window and open the blind a small amount. If there isn't enough light coming in, you can use flash (placed outside the door) to boost it, but if you pop a flash off inside the room, you'll find it hard to keep it from bouncing everywhere, even with a snoot, barn doors etc.
If you're in a studio you can use black foam board or anything else light-absorbing as a flag. Remove all light except through a small slit.
The disadvantage of flash is that you can't easily see what the result will look like. With ambient light you can adjust the flag(s) and see the effect immediately.
Is proper setup all that is needed or additional gear too?
Mostly, it's a matter of eliminating ambient light so that most of the face and background go all the way to black, and the edges of the face are lit by the flash. Faster shutter speed, smaller aperture, and lower ISO are all possibilities.
If the light from your flash is harder than you want, then you'll want something to diffuse it. That could mean additional gear (e.g. an umbrella), but there are plenty of possible light modifiers that don't really count as "gear." You could try a white plastic shopping bag, for example, or bouncing the flash off a white wall or a piece of foam core.
