RockU Friday: Painting with Light

by Meredith Wright


  1. Digital SLR (or any camera that allows for adjustment of exposure time)
  2. Tripod or sturdy surface
  3. A room that is very dark
  4. Flashlights or other materials that emit light
  5. Kids or kids at heart

I watched with amusement as students filed into the Carson Family Auditorium at Rockefeller University. Their tiny heads bobbing barely above the chair backs, their toes not touching the floor. The excitement that these small students displayed, far exceeding their physical size.


A few weeks ago, the Science Outreach Program (SOP) at Rockefeller hosted the final Friday night science session for children of Rockefeller employees. The program, dubbed RockU Fridays, caters to K-8 children and aims to teach about science through hands-on activities. This last session focused on the principles of bioluminescence–that is, when organisms give off light. The Lead Scientist of the SOP, Beth Waters, first took the children through an overview of bioluminescence. She explained that organisms create light for a variety of purposes, from attracting their prey to communicating with other organisms. Beth gave some examples of bioluminescent animals (I was surprised how well the children could identify the anglerfish, which made a cameo in “Finding Nemo”), and emphasized how the these animals’ light patterns help them signal to their kin.

After the introductory discussion, the students were able to try their hand at making their own patterns of light, captured using a photography technique called light painting. If you have a camera where you can change the exposure time, you can try this yourself at home. All you need to do is set up your camera on a tripod or other supportive surface and make sure the room is very dark. Change the exposure time to collect light for anywhere from 5-20 seconds depending on the effect you want
to get (we used 6 seconds for our photos). It’s also helpful to lower your ISO, but all of these setting choices are up to you depending on the look you’re aiming for.

Next, grab anything that emits light. We used flashlights modified with colored plastic so that the students would have some options for colors, but you can use any flashlight or even your cell phone screen. Have one person hit the shutter button on the camera while the person holding the light does pretty much whatever they want. Some of our students went wild waving their arms, others ran from side to side, while others tried to make specific shapes. You can check out our slideshow to see the results of the students’ creativity.

This type of photography allows you to create all sorts of shapes and patterns with light, much like the bacteria and other bioluminescent animals that the children were emulating. While traditionally used in artistic settings, this technique proved to be a great teaching tool for a curious biological phenomenon. We hope our photos inspire you to learn more about bioluminescence and try creating light painting images of your own.

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