A bounce umbrella works very simply by taking the light from a light source and expanding it’s spread.
A bounce umbrella is typically lined on the interior with a silver, gold or white reflective surface and on the outside with black to reduce light from escaping.
To show you exactly I’ve put together some diagrams that show where the light goes. For this example we’ll assume that an umbrella is a cut of a perfect sphere. The focal point, through which all the reflected light passes, is 1/2 * radius of the circle, or half way between the sphere’s center point and the edge of the umbrella.
When the light hits the reflective surface it bounces back in a straight line through the focal point.
You can see where the reflected light hits the subject.
At first you’d expect to want to place your subject at the tip of the umbrella (like shown in the diagram) but that’s rarely the best idea – we’ll cover that in another article.
Check out our sister site, Single Strobe Photography to find some great shoot-through umbrellas to buy through some of out favorite online retailers, B&H and Amvona.
Ken says
December 26, 2009 at 6:21 pmNice! I’m glad I subscribed to the feed after reading the post like this one about the shoot through umbrellas. I hope you have more diagrams like this about lighting showing where the light goes and how it gets there. Shoot me an message and I’ll tell you what Id like to see!
TJ McDowell says
September 14, 2010 at 9:06 pmWe shoot with a couple umbrellas in the studio and a few softboxes, but we usually shoot bare on location. Do you usually recommend umbrellas for location shoots too?