I’m sure you have seen these absolutely stunning pictures of star trails before. Maybe you even wondered how star trail photography works. I have seen pictures of star trails in the internet and thought:
I want to take photographs of star trails
My first trials where complete rubbish and I was very disappointed in the results I got.
In the beginning I just started to take some images without any knowledge. I set the shutter speed to the maximum of 30 seconds and expected to see at least some star trails. There were only some small, blurry dots on the image but no real star trails.
In the next attempt I changed the mode of the camera to “bulb”. In this mode I was able to change the exposure time to much longer times than the 30 seconds. I started with five minutes. Now I got at least some short trails. I increased the exposure time until I got up to one hour. Now I really had some star trails on my images. Unfortunately I got a new problem. The sky was no longer black but became too bright with a lot of small, colourful dots called noise.
So now I really needed some help to get better images of star trails. I started to look around on the internet and found many good websites with a lot of useful information on star trail photography.
With my new knowledge I started again and already my first trials where much better compared to what I got before.
Tips for star trail photography
If you want to take pictures of star trails, here are some tips that will help you to get better images. There are different methods for taking pictures of star trails. All methods involve a lot of time and you need patience. Don’t be frustrated if the first trials are not as nice as you expected them. Change your settings and try it again and again.
Different methods for taking pictures of star trails
One image with a very long exposure (15 to 60 Minutes)
Set your camera on “bulb”, ISO 100, f/22 and exposure time to 60 minutes for a start.
Advantage: Easiest way with no post processing
Disadvantage: You will end up with a lot of noise because the sensor will heat up and that will cause hot pixels on your image
Multiple images with medium exposure times that will be combined in post processing
Set your camera on “bulb”, ISO 200, Aperture as low as possible (i.e. f/2.8, f/4, f/5.6) and exposure time to 5 minutes for a start. If you see some short star trails on a dark sky in your test image you can continue taking a whole series of images without touching your camera.
Advantage: If you do exposures of 5 minutes, you can cover an hour with 12 images.
Disadvantage: You will end up with gaps of some seconds between the different exposures.
Multiple images with short exposure times that will be combined in post processing
Set your camera on ISO 400 to 800, f/5.6 and a shutter speed of 30s for a start. Now you need to shoot 100s of images taken with as little gaps between the shots as possible. You can achieve that with an intervalometer, a remote, a cable release, a camera controlling SW or a cheap rubber band that presses down your shutter.
Advantage: Very short gaps between the individual images
Disadvantage: You will end up with a lot of images. If you do exposures of 30 seconds, you will end up with 120 images to cover an hour.
For me I’ve found that the best way to photograph star trails is to shoot multiple exposures of 5 minutes and combine them later with software. That is the method I’ll be explaining later on.
Composing a star trail image
Depending on the direction you point your camera for a star trail image, you will get completely different results. If you are taking pictures in the southern hemisphere, like I did in Australia, it is the opposite of taking start trail photos on the northern half of our planet.
Star trails with the rotation centre or the Pole Star in the frame
If you want to have the rotation centre of the star trail circles in your frame, you have to locate the North Star or just point your camera to the north in the northern hemisphere. If you are in the southern hemisphere, you have to point south. Remember that the stars rotate much slower towards the centre of the circle, so you will need to have a longer exposure.
Parabola star trails
If you don’t want to have the rotation centre in your frame, just point your camera away from north (or south respectively). The stars will pass by much faster and you will get really nice, long star trails with a shorter exposure time.
6 steps for taking star trail pictures
- It’s best if you use a wide angle lens
- Set your camera to “bulb”, ISO 200, lowest aperture (i.e. f/4.5)
- The first thing to do is establish focus. Point the camera at a bright star or anything that is far away and focus on that. After focusing switch to manual focus. Or set your camera to manual focus and focus out into infinity
- Compose the image by pointing your camera into the sky but including some landscape to create perspective.
- Start shooting. With a remote you can start an exposure and stop it after 5 minutes. Immediately start the next exposure. Try to be as accurate as possible with the 5 minutes intervals.
- Combine the single exposures with software like Photoshop, Image Stacker or Startrails. I personally use Startrails because I like the results and it’s for free.
Things you will need for star trail photography
- DSLR camera with a wide angle lens
- A good, sturdy tripod
- A remote shutter release
- Clear dark sky with as little as possible light pollution
- A lot of time
- A software tool to combine the individual images
I hope these tips help you to get started with this interesting aspect of photography. Or maybe you have already experimented with star trail photography and have som tips that you would like to share in a comment?