Concentrating light asks us to do exactly that, buy placing a cardboard tube or cone around the flash in my case to focus the light into a smaller area in a single part of the scene. This is to be achieved making a card tube ‘snoot’ around the end of a flashgun to focus the light into a smaller area than normal. This exercise is unclear on the number of images so I have assumed 1-2 shots.
Equipment used Nikon DSLR, 105mm lens, speedlight flash, card tube, white card as a reflector and light stand.
Low flash and camera angle has created the appearance of a long narrow line of light isolating the subject.
Much higher angle this time for both camera and light, with a very small aperture on the snoot to create a small point of light.
Widening the snoot aperture this time and framed so only the foreground is illuminated. On all these shots there is a white card just out of shot reflecting some light back into the shadows of the model.