We're going try to show you how to use an artificial light to illuminate a moving person's face at first from one side and then from another so that the rest of the body remains totally dark.
For this we used three Dedolight focusing lights - one of them with an Imager Protection attachment DP1.
As the walls and the ceiling were white, they reflected light easily so we needed to create a quick mini-studio.
We used two black curtains and placed on the both sides of the object we wanted to illuminate. Just as you see on the picture. We placed the Dedolight Focusing lights according the red spots on the image on your screen.
We illuminated the background using the Dedolight Focusing light with an Imager Protection attachment. Using Maximum dimming we were able to decrease our camera aperture and increase focusing distance. But most importantly we received a Silhouette of our actor on the screen.
You can control a diameter and a focus of the background light using the image protection attachment. Our main goal was to direct the light so that it could not illuminate the starting point of our object.
Or you can get effects like this - depending on which genre of cinematography you are involved :)
Finally we directed all three focusing lights according this scheme:
The #1 red spot on the picture represents the focusing light with image protection attachment, which we have already talked about.
On the other side of the curtain we placed two focusing lights. Each of them illuminates different parts of our objects walking trajectory.
Our task was to direct the lights so that their rays could not cross or meet each other. We closed the curtains of the Dedolight focusing light kits to narrow the ray as much as possible.
Although our black curtains held the part of the rays form each side, on our first try we found out that at one point the face of our actor was fully illuminated.
So we created additional Barriers for the lights. For that you can use any Nontransparent object which can reflect light. Size and position of the barriers depends on how much light you want to "cut" with it.
As result we got most of the rays reflected either on the black curtains or on our additional barriers and only little part of it was reflected on our actor's face.
As we built the additional barriers we partly received the result we needed. The #2 and #3 focusing lights appeared too bright and it was reflected on our actor's white T-Shirt. On the other hand our task was to achieve the result without using any Dark clothes or Dark walls.
Finally we reduced the dimming of the #2 and #3 lights from Maximum to Half and used following settings on the Camera:
Shutter Speed - 50, Aperture - 8, ISO - 1600.
And we had our result.