This is a lighting technique which I would like to share to some people who have been asking - how to light a black subject on a black background in low key style. Using your flash mounted on its hot shoe or doing a wireless remote lighting even in CLS fashion won't get you this softly diffused lighting. Even using light modifiers like honeycomb, snoot or soft box can't get things right either. So, how did I do it?
Light painting must be the answer. How did I set it up? well, you must do it at night in a room without any stray light. Of course, you can do it on a day time as long as you keep the daylight away. Put on a sturdy tripod where you can mount your camera. Tripod is the key equipment to this lighting technique because you will set up your camera in a long exposure release mode using a self-timer to trigger the exposure.
In the first two photo samples here, I randomly picked 6 seconds as my shutter speed. The shutter speed you will choose should let you have all the time you will need to paint your subject using your chosen light source. Since you are exposing your subject in a longer time than usual, you should also pick a smaller aperture so that light will pass through slowly into your sensor. The choice of a smaller aperture would likewise give you a deeper depth of field which is important in product photography where details of the product should be emphasized or made readable.
And now this is the clincher - what light source did I used in painting my subject? Well, since I'm a Nikonian, I can only experiment using my speedlights on hand - the SB800!! I fitted it with a snoot but of course without taking off the diffuse dome to make the light softer. Then using its modelling light by snaply pressing its button, I painted my subject with light coming from the localized light of my diffused flash. Six (6) seconds is more than enough for you to circle around your subject and get the illumination you wanted.
To show you the difference of doing black on black using a lighting technique other than painting with the light, I posted this third sample photo where I used my SB800 mounted in a soft box and wirelessly triggered in CLS. Despite using a manual flash setting of 1/64, the harshness of the light can still be seen despite diffusing the light with a softbox. Light painting is therefore the better technique because it can give you more latitude on experimentation.