|Finding and Photographing Rainbows|
Rainbow physics answers the question, "How Does A Rainbow Work?" Understanding how rainbows form can help in your quest to find and photograph them, though it's not essential. I'll attempt to explain the physics of how a rainbow is formed without getting too dry and technical. Still, those allergic to physics can skip this section. And those well-versed in physics, please pardon my simplification. As always, corrections and clarifications welcome!
How A Rainbow Works: Refraction and Reflection
Two physical phenomena are at work within a rainbow: refraction and reflection. Refraction occurs each time light passes across a boundary from one substance to another, such as from air into water. As light crosses that boundary, the rays bend at different angles depending on the wavelength (color) of light. This is the familiar prism effect wherein "white" sunlight is broken into a spectrum of different colors from red to blue-violet.
The same thing that happens in a rainbow: white sunlight enters a raindrop and is broken into different colors heading in slightly different directions. The light is then reflected (and magnified) off the back of the raindrop and passes back into the air again, in the process being further refracted.
Now look at an adjacent raindrop: it's also shining blue light at us. In fact, all of the nearby raindrops appear blue from where we're standing.
But if we look at a single raindrop in the RED band of the arc, only the red light is shining our direction. In between blue and red, we find "all the colors of the rainbow" refracted and reflected from countless raindrops in just such a way that they shine our direction. Beyond the edge of the arc, where we see no color, the raindrops may be emitting colored light but none shines in our direction.
Continue with Part 5. Rainbow Angles.
|Updated 20-aug-11 Contents copyright © 2001 - 2011 PhotoCentric.Net, All Rights Reserved|