Line Art with Light
December 12, 2007
Randomly scattered streaks and vehicle light trails are some common examples of delayed exposure photography that use lights to create some dazzling effects. But for Spandan, Ami and I came up with a new way of using this technique to create what can be classified as digital art, and not pure photography.
The goal was to create line art, using a tiny light source as the marker, and the camera CCD as the canvas.
This activity requires two people – one to man the camera and the other to actually draw the lines.
For the subject, choose a drawing with clear outlines. We used pictures of sea creatures from an old children’s colouring book. The light source can be any small point of light such as an LED torch or even an incense stick. The advantage with the LED is that you get to set the colour at the time of exposure.
See more photos in this series here and here.
Place the drawing upon the floor on a plain black background. Place a sheet of transparent glass on it to hold it still. Note that the glass often reflects the light from the source, and this may or may not be a good thing, depending upon what you are doing.
Clamp the camera onto the tripod and position it over the glass sheet. Point the camera downwards and frame the subject carefully. Once positioned, don’t move the subject or the camera.
Turn off all lights in the room. Also block out any ambient light from the windows by covering them with a dark cloth or taping black paper upon it. If you don’t have a dark room available, performing this exercise at night yields better results.
Now put your camera into bulb mode, or its equivalent. We used a Canon PowerShot A530, which doesn’t have a bulb mode, but did have a manual exposure setting of up to 15 seconds. So we drew individual lines in this given time then layered everything together during post-processing. Then release the shutter and let the other person begin trace the lines on the paper with the light source.
If your camera goes into bulb mode you can complete the entire drawing in a single shot. To do this, ask the person to indicate when a line is complete and she would like to reposition the light source. At this point, cover the lens with your hands while the light source is being moved. Uncover it again to capture the next line being drawn.
If you have captured lines separately, layer them together in Photoshop or GIMP. You can set the layer mode to Screen in order to automatically mask out the black areas.
Drawing and Exposure Techniques
Some people say that this art form is something akin to painting, but I don’t agree entirely. While in painting, the intensity of the stroke can be controlled by several factors such as brush pressure and viscosity of the paint, the controls are not quite as intuitive with light painting. Intensity of the stroke must be varied by the sensitivity of the recording surface (film or CCD), the aperture size, intensity of the light source, and the speed with which it is drawn. Fast hand movements make for thinner, lighter strokes. Slower movements give thick, intense lines.
As with any other form of line art, it helps to have steady hands when tracing the lines. My wife does a great job of this because of her art background. Fast strokes are generally smoother than slow ones. But because of the way speed affects the exposure, you might need to compensate fast speed with a brighter light source.
One must also watch out for not damaging the shot by too intense a light. Pixels can literally be burned out into solid white because of overexposure.