Registered: Nov 18, 2002
Total Posts: 8551
Country: United States
In a small white room you can just bounce light off the walls and ceilings to create uniform lighting. A few years ago a furniture maker who was trying to do product shots on a white background with only two lights asked for advice.
What I suggested was using a small reflective room with a combination of bare flash to fill the room with even light, but also with a point light source directional component, combined with backlight for shape definition. I grabbed a table, and in about 10 -15 min shot this demo:
Set-up:
The foreground light is an AB800 pointed straight up with just the exposed flash tube. The rim light is a small 16x22 Photoflex SB with a circle mask and 40 degree grid: what I normally use as my "hair" light for portraits. I put the table on a raised draped platform to minimize shadows beneath it. Just a "quick and dirty" demo...
Just the bare bulb flash:
Just the bare bulb flash w. some Photoshop work:
Bare flash + back-light:
Bare flash + back-light w. some Photoshop work:
Conceptually you want to start with the same lighting you'd get outdoors on an overcast day, then subtract light from the directions where "shadows" are desired. We perceive 3D shape in 2D photos by reacting to contrast differences. The rim light will enhance the illusion of 3D shape by outlining the form of the object with specular highlights. But in the case of white backgrounds the background "white" must actually be "off-white" around 250.250.250 to allow the rim light contrast to be seen... Heres a set of illustration I did in the same thread to illustrate how the brain translates contrast pattern into the illusion of shape:
What you'd see with a table leg illuminated by a single centered diffuse source in a dark non reflective space:
Adding rim light from both sides will enhance the illusion of 3D. You'd typically get that effect just from light bounced off the background or wallls:
But as rim light intensity increases edge contrast is loss and the rim light becomes counter-productive causing the edge definition to be lost in to the similar background.
The problem is a lack of contrast at the subject/ background border. The solution? Make the background darker to increase the contrast at that border:
At some point, which can only be gauged by eye in the final reproduction, there will be an eye-pleasing balance of contrast between foreground and background which at the same time creates a very realistic illusion of 3D shape on the object in the foreground.
Once we understand the role of contrast and how it tricks the brain understanding where to put the lights becomes simple because what the light is actually doing inside the brain of the viewer is better understood. The "craft" of lighting is nothing more than consciously and thoughtfully understanding what we react to sub-conciously and emotionally every waking moment of our lives. Work smarter and you don't need to work harder
Chuck
