Steps for Star Trails Photography
- Focus your lens to infinity.
- Aim your lens a the sky. Pro tip: Use a sturdy tripod.
- Shoot multiple 30-second exposures. Try to shoot at least 30 minutes for best results.
- Process your images using Adobe Lightroom and export JPEGs.
- Stack the shots in Adobe Photoshop and set the blend mode to Lighten.
Be sure the sky is clear
Check if the sky will be clear and there is a new moon or no visible moon. However, rules are made to be broken, and clouds may add some drama to your photos.
You can check the clear night skies forecast at Clear Dark Sky
Standard Exposure Settings
Here are some exposure settings for common apertures while taking night sky shots.
Camera Crop Factor
Using a camera with a full frame sensor is ideal, but here are the crop factors for popular SLR cameras.
- Consumer Canon = 1.6
- Consumer Nikon = 1.5
- Full frame camera = 1
Zoom Levels and Star trail lengths
45 minutes to 1 hour is a good minimum time length for shooting a star trails photo. Using wider lens (14mm) makes the stars appear to move less.
10 minutes will show much shorter star trails, but it depends on what effect you desire.
Rule of 500 or 600 for minimal star trails
Shooting the night sky as it is can produce stunning results, but streaking stars can ruin a milky way photograph. This rule will help you determine the maximum exposure time for minimal star trails.
Determine your FOV (field of view)
- 18mm multiplied by Nikon Crop (1.5) = 27mm FOV
- 18mm multiplied by Canon Crop (1.6) = 28.8mm FOV
- 18mm multiplied by Full frame (1) = 18mm FOV
- 14mm multiplied by Full frame (1)= 14mm FOV
Convert to exposure time
- 500 / 27mm = 18.5 seconds
- 500 / 28.8mm = 17.36 seconds
- 500 / 18mm = 27.78 seconds
- 500 / 14mm = 35.71 seconds
Focus is Key
The best method is to set your focus before you go shooting.
Another method to double check your focus is to:
- Set the ISO very high.
- Shoot one frame (photograph).
- Zoom-in with your display to see if it is in focus.
- Repeat until you are happy with the focus.
Shooting the Milky Way
The Milky Way will look breathtaking if it is exposed correctly.
Download Stellarium to see where the milky way will be before you go shooting.
Foregrounds are essential to creating an outstanding shot. You may want to bring a flashlight, strobe, or off-camera flash to help expose the foreground subject. Be sure to check the color of the light that comes from your light source, as it may throw off your color balance.