How to make decorative lights twinkle like stars

December 16, 2019
     How to make Christmas Tree Lights twinkle like stars as in the above image?   Decorative lights are so pretty at night but it can be hard to recreate their sparkle in photographs. Here’s the technique for achieving just that—the secret is in the aperture!  Here are the instructions to make the lights appear like starbursts.
      First make it dark by turning off the room lights and shooting at night.  Mount your camera on a sturdy tripod and use a cable release to reduce camera shake.  If you don’t have a cable release, you can use your camera’s two-second timer to release the shutter.  I set my camera’s ISO to 1600.  Use aperture mode or Manual mode and set the aperture to f/22 (The camera’s aperture is a very small hole.).
      In the dark your camera’s autofocus feature may be confused and continually search for focus or not work at all so set your lens to Manual Focus and focus manually on the lights. On my Canon 80D camera, I use Liveview mode so I can view the image on the screen on the back of my camera.  Liveview helps me to compose the image and focus when the camera is on the tripod.  Start with a long time exposure of 5 to 10 seconds and check the picture for exposure.   Adjust the shutter speed if you need but leave the aperture at f/22.  Experiment with different shutter speeds.
      The key to the starburst effects is using the very small aperture of f/22. If you use an aperture that is narrow enough, e.g., f/22, the image captured will have obvious rays of light extend out from each light source, making them appear like stars. This is known as the “starburst effect.”  The number of “points” that your starburst  has (i.e., the number of rays of light that extend from the light source) is dependent on the number of aperture blades in your lens’ aperture diaphragm. An even number of aperture blades results in the same number of starburst points, whereas an odd number of blades results in twice the number of starburst points.  My Canon 18-200mm zoom lens has six aperture blades which creates starbursts with six points as seen in the above image.  Any lens you have will work.  However, your lens may create starbursts with a different number of points.
       Enjoy taking photos of decorative lights such as Christmas lights and candles.

Posted by Dan Hyde

Dan is the Chair of the Lewisburg Photography Club.