For night sky trail photography, use a wide lens at its widest aperture, an ISO around 1600 to 3200, manual focus set at infinity, and a series of exposures of roughly 20 to 30 seconds each on a sturdy tripod. You then combine the frames into one image showing long arcs of light. These numbers are general guidance to adjust for your conditions.
Two Ways to Capture Trails
The first method is one very long exposure, which can run many minutes. It is simple, but sensor noise and heat build up, and one bump ruins the whole shot. The second method is to take many shorter frames back to back and stack them in software. Most photographers prefer stacking, because a bad frame can be dropped and the noise stays lower.
Recommended Camera Settings
- Lens: a wide angle, roughly 14mm to 24mm on a full-frame camera, with an aperture of f/2.8 or wider.
- Mode: manual exposure and manual focus.
- Exposure per frame: roughly 20 to 30 seconds. As a rough guide, dividing 500 by your focal length gives the longest time before points of light begin to streak in a single frame.
- ISO: roughly 1600 to 3200, lowered if the sky is bright from a moon or town lights.
- File format: raw, with in-camera long exposure noise reduction turned off when stacking, since it adds gaps between frames.
- White balance: a fixed value, such as roughly 3800 to 4500 Kelvin, so every frame matches.
Step by Step in the Field
- Find a dark location, away from town glow, and set up a stable tripod.
- Frame your shot. Pointing toward the pole of rotation makes circular arcs, while other directions give straighter lines.
- Switch to live view, zoom in on a bright point of light, and turn the focus ring until it is as small and sharp as possible.
- Set the exposure values above and take one frame to check brightness and sharpness.
- Connect an intervalometer or use the camera’s built-in interval function. Set it for continuous shooting with a gap of one second or less between frames.
- Run the sequence for roughly 30 minutes to two hours, depending on how long you want the arcs.
- Stack the frames in editing software that supports a lighten or maximum blend.
Practical Extras
| Item | Why it helps |
|---|---|
| Intervalometer | Runs hundreds of frames without touching the camera |
| Spare battery | Cold air drains batteries quickly |
| Lens warmer | Helps reduce dew on the front of the lens |
| Large memory card | Raw frames add up over a long session |
FAQ
Why are my trails broken into dashes?
That usually means a gap between frames. Reduce the interval to one second or less and turn off long exposure noise reduction.
Do I need a special camera?
No. Any camera with manual exposure, manual focus and an interval option, or a connected timer, can do this.
The Short Version
Use a wide, fast lens, manual focus at infinity, ISO near 1600 to 3200 and frames of roughly 20 to 30 seconds. Shoot a long continuous series and stack the images. Treat every value as a first guess for your own sky and location.
