So now that I've got a slightly more capable DSLR body I have a few more techniques available to me, primarily those that require - or work out better - with an off camera flash. As a result, in my ever continuing awesomeness (or sadness depending on how you look at it, I suppose), I ended up spending this valentine's weekend messing around with one of those techniques, the "invisible black backdrop".
These photographs are fairly easy to pick out: all black backdrops with a single subject with focused lighting. I've always thought these kind of photographs were fascinating, but most of them seem to be taken in a controlled studio with a black backdrop so they always seemed out of reach. Luckily there is a technique that one can use to get the same look, using just an off camera flash and some nice manual settings on the camera.
Basically, you setup an off camera flash with an attached snoot or grid (or both!) in such a way that any extra light spills out of the shot frame; a flash that is perpendicular to the camera is what I used since it was the easiest to manage for my location. Then you setup your camera to use the fastest shutter it can stay synced with your flash at, the highest f/stop (or smallest aperture if you want that terminology) and a low ISO. You want to get these settings setup so that when you take a shot without the flash, the whole image is pitch black; This way, when the flash does fire, the only light you should get is from it.
Using a snoot or a grid on your flash to focus it is pretty important here too, since you don't want any of the light spilling onto whatever is in the background, causing it to also show up in the photograph. This is also why you want to use an off camera flash: so you can ensure that you aren't lighting up anything else the camera can see, except the subject.
I'm trying this out from my grandparents house this weekend, so I was working on not only tight space (only a small 10x10ish bedroom with a queen bed taking up a lot of it) but also limited gear. As a result, I had to make an impromptu snoot out of some cardboard, and hang my flash from the edge of a door using the gorillapod I bought just for situations like this.