2015.1.20.parabola.trial.lh-1007 2015.1.20.parabola.trial.lh-1006 2015.1.20.parabola.trial.lh-1002

Ever since I first saw this project posted online, I have thought it would be a fun one to do with students, especially if they were studying the science behind the pattern a swinging object inscribes in space.

I got my chance when I was asked to present a project for Woodberry Forest School’s photography club.


I’m writing down the techniques used so that students may refer to these notes in case they want to experiment further.

Other helpful resources are:




You will need:

A very dark room. We used the school’s dark room.

A small flashlight.

Some string with a way to attach it to the ceiling.

Colored tape.

A dslr camera that can be set to manual

Some different colored gels with a rubber band to place them on the flashlight (the drama department gave us some extra light gels and scraps in different colors.)

A black piece of cardboard or a board covered with gaffers tape.

Camera settings:

Aperture: f/22

shutter speed: bulb

ISO: 200 (unimportant)

Lens: use your widest angle lens.

Focus: manual, set to approximate distance using the focus ring on the lens.


Hang the flashlight from the ceiling.

Position the camera on the floor facing up.   Use tape to mark the position and adjust as needed so the camera is directly under the flashlight.

Turn on flashlight.

Turn off lights.

Activate shutter, possibly with a timer delay so that the motion of pressing the shutter will not be captured.

Try a shutter speed of at least 30 seconds and up to four minutes.

Experiment by covering the lens with the black card and then rethrowing the flashlight in a different direction, covering the flashlight with a gel, or changing the length of the string. I think it might be interesting to add a spring to the string or change the length during the exposure. It might also be cool if you had a light that flashes on and off.

Photo Competition Information:

If there is interest, Woodberry students may participate in the AAPT photo contest. Up to fifteen from our school may enter. Please talk to me if you have a photo you’d like to enter. If necessary, we will have an in-school contest to select the best photos to enter into the competition.

See the rules here: http://www.aapt.org/Programs/contests/photocontest.cfm