Long Exposure Of Laser Through Water Drops

Sometimes the most amazing things happen when you leave your shutter open for a long duration. Especially if you do it in the rain, while pointing a 200 mW Laser across it.

Light painting master Jeremy Jackson went for a “regular” laser light painting in the rain and came across an interesting phenomena. The drops diffracted the light and created snow-flake-like patterns when the laser hit the drops.

Here is how Reddit user Staus explains it:

“It’s from the light wave interfering with itself. Light is a wave. Waves constructively and destructively interfere with each other, depending on the relative phase of the waves that are interfering. Laser light is coherent, meaning it’s all in phase to start with. When light hits something that scatters it, like dust in the air, the air/water interface in a rain drop, or probably the regular pattern in the chip of your camera, the wave gets spread out. When these spread out waves recombine some have traveled farther in space than others, so some of those waves have shifted in phase with each other. As a result when they recombine there’s constructive and destructive interference, which you see as that banding pattern. Different rain drops are different sizes and different distances from the laser beam, so they look different from each other.

The name for this is diffraction, as pointed out. #

If you clicked the image above and aid a visit to Jeremy’s stream, stick around for a while he has some amazing light painting photographs.