Now that you have your light set up for the model and the reflection of the object on the background, it is time to determine the ambiance your wish to create. If you are looking for a more “Cinema Noir” look you may wish to isolate the foreground from the background by increasing the out put of the flash on the subject and letting the background go darker by another 1 to 2 stops. But this may also pose other problems that I call “light bleed”. The spread of light throughout the space by virtue of light bouncing off of surfaces around the space. What I suggest you do here might be the following.
Take some aluminum foil and form it in to a conical shape to reduce the size of the area that the light will cover. If you have thin sheet metal, this might prove to be more controllable, as you can adjust the circumference of the opening to your taste. Another approach is to take a piece of aluminum foil and place it on the front of the can facing the model and poke 10-20 “Bic” pen width holes in to it to produce “specular” light. This will of course reduce the flash output considerable and as a result you may wish to augment the shutter speed to compensate, as this will effect the proportion between the foreground and background.
It is very important that you do not spill too much light on to the back ground, as it will negate much of the shadow produced by the background light being cast on the wall. For this I suggest several possibilities. One, is to raise the light about three feet above the subject and shooting down at around 60 degrees. This may work well, if the wall is at least 5 meters behind the subject. I love side lighting and although not always becoming to the model, it does add a very mysterious feel to the image and gives the background more drama, as there is very little light bleed from the principal light source. You may wish to introduce a lamp in to the composition to act as the “Faux” source of the light casting the shadow on to the wall. Very Hitchcock looking.
One of the most important parts of a shoot is keeping open to the possibilities when shooting a subject. Now even though you set up the lights to be in a certain position, based on the fact that you will be shooting from the opposing position, I would also suggest considering another approach as well, which I will discuss in the next segment of this series.
I will see you for part 5 shortly.