I call it the 30 second portrait, and I've used it a number of times, and it doesn't even take 30 seconds.
It works just as well for a quick head shot, a child's first day of school, a bride, or in this case, a dancer at the Annual Grand River Pow Wow.
Photography is not just about light, but also the ratio of the light.
In this case the subject is standing inside the opening of a large garage door, waiting for his competition to begin. Although there's no sunlight directly on him, the light flowing in the doorway easily lights his face and gives the great detail on his clothing. The background was just further in the doorway, but the light was falling off and creates mostly dark tones and colours. Had the background been of equal luminance the lighting wouldn't have worked as well. If he was standing further out of the doorway and in the direct light the photo would have too much contrast and he might have been squinting.
The lens I used was a prime 135mm F1.8 Zeiss for the Sony A900 full-frame camera. The picture was taken at F3.2 on aperture priority with the ISO set to 200 and the "Super Steady Shot" stabilization turned on. This lens is very sharp wide open at F1.8, but by stopping down to F3.2 I gain a bit of sharpness and a touch of depth of field. If I shot this photo at F8 the background would have been too in focus and the sharpness would have added confusion and taken away from the photo.
If I'd have used a shorter lens, again the background would have been sharper, the background would have covered a wider field of view (which included lights and exit signs) and the subject's face wouldn't have looked as good. It I had a longer lens, I would have been too far from the subject to offer directions and other people/dancers would have been walking between us.
Is it perfect. No, but not bad for 30 seconds.