Parasols: High-Speed and Hopefully Interesting

The Parasols are high-speed photographs of colliding drops of liquid. This type of photography presents a number of technical challenges starting with the type, viscosity, and color of the liquid being used, the sizes of and timing between drops used to produce the collisions, and with timing the precise instant at which the image is recorded. Small changes in the sizes of the droplets or the milliseconds between drops make a world of difference in the result. Yes, I said milliseconds.

Lighting is another big issue.

In most types of photography, motion is frozen, or not, by varying the shutter speed. Very few cameras, even the most high-end professional cameras, have shutter speeds fast enough to freeze the motion of drop collisions. Even if they did they would still not be able to produce high quality images without intense, controlled lighting. Instead, very short, intense bursts of light are used to both illuminate and freeze motion. By short burst I mean around 1/18,000 second. To produce bursts this short involves using speedlights (small, portable flash units) set on near to their lowest power settings (which produce light in the shortest bursts). Since they are set to low power, they produce less light so this needs to be offset by the addition of more flash units. Wait, there’s more…the flash units need to be identical in order for their bursts of light to occur at precisely the same time -- if they are slightly out of sync there will be ghosts from the various timings of the pulses of light.

These images were shot using six identical speedlights controlled wirelessly from the camera, four back-lighting a white, translucent piece of acrylic for the background along with two to illuminate the front of the droplets from either side. These were photographed in a darkened room with the shutter open for the entire duration of the drop sequence but using the flash duration to freeze the motion.

Of course, none of the technical challenges are of any importance unless the images are interesting. I think these are interesting and I hope you agree.