Tutorial : Star Trails

16Apr07

Hi Everyone,

One thing I love in Long Exposure photography is the trails stars can leave in images. This quick tutorial will let you know the factors you need to get great results.

Firstly, I think you need to see the photography I’m talking about, (if you haven’t already seen it, or imagined it). This photograph from ‘velvet paw‘ shows the beauty star trails can show in images:

There are many physical factors that help hugely in taking a long exposure photograph with star trails, so before you can start to think about what you need kit-wise, you need to know about what weather and location is necessary.

  • Little or no Clouds

Clouds in a picture of star trails can be very attractive, but too much and it defeats the point of the image. Realistically, I’d probably only consider doing a long exposure with star trails if the weather was cloud free, and it there were clouds to come along, chances are they wouldn’t be particularly ruining to the image.

  • Clear, dark Skies.

You’ll find that to get the best shots it has to be very clear, even when there are no clouds, chances are, if you live anywhere near a built up area, that there will be significant light pollution preventing the best image possible, therefore, you may need to travel to get to the best location. I’ve found that on many occasions I’ve started off an exposure, and by the time its done have the shock of discovering the ambient light was too much, and the star trails have been washed out by it.

  • A subject is pretty much required.

I find that a long exposure performed solely or predominantly for capturing star trails can be incredibly uninteresting if there isn’t a subject in the photograph. Again, returning to the fabulous image of Mt. Fuji, the subject makes the image. I find that you don’t need an amazing subject, but having one is pretty much a necessity, cars can be cool subjects, if they are well cleaned, you get reflections of the star trails, and the same goes with water.

Next is the kit you will need for the images. Realistically, you need a prosumer or SLR camera, (?), with a Bulb function, (often shown on the camera as B). You can easily discover if you camera has this function by turning it on, switching to the M position, (fully manual). Then turn the shutter speed as slow as possible, and often, after the slowest speed the camera does, you’ll be shown a B, or Bulb:


You can see the display on my 400D above. The bulb function means that the shutter stays open as long as you have got the shutter button pressed down. This means that you would be holding down the shutter button for a long time, and thus you may wish to purchase a shutter release cable, that can allow you to lock the shutter button down and keep it open whilst you wait. An example of such a product can be found here.

If your camera has this function, and you’ve sorted out a way to hold your shutter open, I can move on to a quick list of what you will need:

  • Camera with Bulb Function
  • Tripod
  • A subject
  • Time 🙂

With those things you are pretty much set to go, oh, there is one last thing, you will find with digital cameras, the battery will run out eventually, so if you are planning to take many, try and take a few back up batteries, or if you can some form of mains power.

The method for this ‘genre’ of photography is very simple really, you will want to set up your camera, looking at a subject that you have chosen for the photograph. The camera should be atop a tripod, and preferably have a cable release attached to it, to allow the camera to stay on for a while without your intervention.

Now, lock the shutter down, and your camera, well, most cameras will display a time on the screen like this:

This allows you to see how long your shutter has been open, and therefore how long your exposure has been so far. I find that it is best to leave your aperture wide open, (smallest f/number), and then to experiment with the timings, as the brightness of the stars varies from location to location. This part basically requires a lot of experimentation, and if it is quite bright and you want longer exposure times, then you get a smaller aperture, and try again. I recommend that you start at around 5-10mins, and depending on your results there, you can adjust aperture, (if necessary), and then increase the time to 30-40mins or more!

For a fairly extreme star trail, you will probably want about a half hour exposure, and something like the above Mt. Fuji photo was probably more along the lines of 10-15 minutes.

I hope that this has been an informative introduction and tutorial into the world of star trail photography. Let me know if you get some good ones!

Charlie –

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7 Responses to “Tutorial : Star Trails”

  1. 1 Paul

    Smashing post – please feel free to post this to http://www.photographyvoter.com

  2. 2 the nerd

    I’ve heard that using a pen cap, and an elastic band can hold the shutter open in bulb mode quite well. I have yet to test it though.

  3. 3 Charlie Styr

    Thanks for the comments guys, and ‘the nerd’ I’m sure there are many ways of makeshift shutter releases, that soulds like a good one, I might try it out of interest!

  4. 4 Melissa

    This was exactly what I was looking for.

    I have the 400D and I am heading to Yellowstone National Park this and will be staying on Lake Yellowstone. I am hoping for some clear nights with the stars so I could try the star trails, but I’ve never used the blub function so YOU TOTALLY HELPED ME IN EVERY POSSIBLE WAY. I will have to try the long exposures the next time there is a starry sky. Thanks so much!

  5. 5 Angus

    Many Cameras have built in long exposure times. I’m using a high end consumer camera, and I have times up to half an hour as presets. This makes it much easier when timing your shots, and also means you don’t have to wake up after trying for a 4 hour exposure (it has been done, believe it)

    You guys might also be interested in time lapse photography, where you set your camera to take a picture every 30 second or so. When you play it back as a movie, you get similar trails. Also looks good when you point it at traffic.


  1. 1 www.autumnaurora.com » Blog Archive » Star Trail
  2. 2 Canon Eos Bundle

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