4 Steps To Creating Star Trails Photos Using Stacking Software

4 Steps To Creating Star Trails Photos Using Stacking Software


If you’ve ever seen images like the one at right and wondered how they are created, this post from Peter Carey helps explain the steps needed to produce your own star trail images.

Creating star trail images is a fun technique that can deliver a wide range of results depending on location, foreground objects and number of visible stars. While the technique can be relatively simple, proper setup and then proper post-processing are essential. To get started, let’s look at the equipment and tools needed for a normal star trail image:

  • Digital Camera, with or without Bulb mode
  • Tripod
  • Remote shutter release with timer (optional, but it helps)
  • Open view of the sky
  • A lack of city lights
  • Image stacking software
  • Patience and warm clothes if you don’t live in the Tropics

Any camera will work for creating images while it should be noted cameras with exposure length control (shutter priority, manual or bulb modes) work best. The remote shutter release unit is best used to reduce camera shake from pressing the shutter release button as it is used off camera (some are even cordless). If the remote has a timer function it is golden for use with this type of photography. A good timer will allow for setting of the shutter speed, number of shots and interval between shots. This is the best unattended setup if you wish to wait some place warm while your camera takes care of the pictures. Image stacking software allows for the overlay of multiple images while combining the details. A few options will be discussed at the end of this post as well as in the comments section.


1. Location, Location, Location

Finding a location away from city lights is an important consideration. As the stacking software will combine light areas of the picture, it’s best to have as dark of a sky as possible. As you can see from the examples in this post, a lot of images are taken in deserts, as is the example at top(Arches National Park, Utah, USA). Once a good location is established check the foreground for interesting subject matter. A shot of just the sky, while cool for a few shots, looses its luster without an Earthbound object to anchor the action. Mountains, trees, mesas, even people or buildings can be used to add some interest to the shot. Make sure your tripod is set on firm ground and not in a location it’ll be bumped or walked in front of.

If you wish to get the circle effect in the photo up top, just point your camera toward the North Star or the Southern Cross depending on your hemisphere.


2. Settings

With your camera firmly in place it’s time to check exposure settings before shooting. In- camera metering is not going to like how things are set up and most settings will need to manually set. If your camera can not focus in such darkness you’ll need to manually set focus either on a close by object or just off of your lens’ infinity setting. This depends on how close to subjects the camera is set. Having subjects further away allows for a larger aperture and better light gathering at shorter shutter speeds, which has its advantages explained in a moment.

Next set the ISO around 200, but experiment as with all settings suggested here. This depends largely on the amount of light and camera being used. If the ISO is too high and the in camera noise reduction less than optimal you can experience a large amount of camera noise that will interfere with the star trails. At best, it means more time in post processing removing the noise.

Shutter speed can be set as low (or high, depending on your point of view) as 1 second or the shutter held open for minutes at a time. I’ve found my camera gets increased sensor noise on longer shots. For me, shots in pitch black over 30 seconds will show ‘hot spots’ on the sensor; colored points that repeat in the same location picture after picture. I’ve found optimal shutter lengths to be between 10 and 30 seconds, but some cameras work well with the shutter open for one or two minutes. Aperture should be as open as you can stand it based on placement of subjects and required depth of field.

3. Modus Operandi

This is where the patience and warm clothes come in. And a remote shutter release if you have one. As the Earth is always moving and those stars keep walking across the sky, you’ll want to keep your shutter releases as close to the end of the last shot as possible. Large breaks will cause blank spots in the trails. This effect can actually be used to your advantage if you become real creative, just make sure it’s intentional. Keep shooting until you have as many images as you desire. As a point of reference, the image at the top of this post is a combination of shots over the course of 57 minutes.

If you have an item in the foreground, there are light painting techniques that can be used to highlight them. Only one frame is needed because of the stacking method. For more on painting with light, check out DPS’s post Tips on How To Light Paint. A lot of fun can be had adding effects to the foreground.


4. Putting It All Together

Now it’s time to let a computer take over. Kind of. The program I’ve found great success with is TawbaWare’s Image Stacker. It is by no means the end all be all, however I have found it very simple to use with great results. Astrophotographers have even more advanced tools they can suggest depending on needs. A quick Google search can provide other options as well.

The premise here is the program will take your batch of photos and then add them all together to render the final image. Anything reflecting light in all images in the batch will show as especially bright in the final image. Individual starts, when moving across black sky, will combine to create the lines that are so captivating. You may also average all the images of just use the brightest pixel from the batch to create an image. Each pass creates a different view of the same batch of photos, so experiment (have I mentioned that before? 🙂 ) Image Stacker will produce a jpg, bmp or tif file in the location of your choice. Those proficient in Photoshop can also stack images, but the technique is a best left for another post.

And that’s it! It really can be that simple and most importantly it’s usually a lot of fun. Ok, there can be some frustrations as well…..planes flying across the field of view, people shining flashlights toward the camera wondering what you’re doing, small animals bumping the tripod unbeknownst to you. But the results are worth the effort so give it a try and post a link here with your successes!


Peter is an avid photographer currently traveling through South America and Japan who enjoys travel, portraiture and wildlife photography. A travel related blog of his past and current shenanigans can be found at The Carey Adventures. He also hosts a Photo of the Day RSS feed found here.

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Peter West Carey leads photo tours and workshops in Nepal, Bhutan, Seattle, Portland, Los Angeles and beyond. He is also the creator of Photography Basics - A 43 Day Adventure & 40 Photography Experiments, web-based tutorials taking curious photographers on a fun ride through the basics of learning photography.

Some Older Comments

  • phil March 27, 2013 07:38 pm

    I made a first attempt at some star trails recently. The best image was 120 times 30 second exposures. The star trail was good but the foregroud was dark. I am thinking next time to try one 5 minute exposure first to get the foreground, then a series of multiple 30 second exposures and stack them. Has anyone tried this with success?

  • Rainer October 15, 2012 02:45 pm

    Star Trail de does not seem to work for me. I press a couple of obvious buttons to do the stack and then some long time later I get a result with city lights but hardly any Stars???!!! Useless!! Give me something that is easy to use and works!

  • Olegna May 28, 2012 12:24 am

    this tutorial is very useful thanks!

  • Anna Patrick September 16, 2011 04:37 am

    Star trails photography are always fascinating! Here are some examples of inspiring star trails photography http://www.photographymojo.com/2011/09/inspiring-star-trails-photography/

  • Che Ku Zainal December 10, 2010 12:36 pm

    I love this images very much & if you've pleasures pleased give me some tips...

  • kalerblind October 22, 2010 08:26 pm

    thanks for the tutorial DPS! here mine.
    and the vid.

    thanks a lot.

  • Gavin Treadgold January 17, 2009 08:27 am

    Re: Using the Southern Cross - that is a very approximate solution to find the South celestial pole. Check out the more details instructions here for using Crux (Souther Cross) and the Alpha and Beta Centauri (Pointers) to more accurately find the point that stars will rotate around.


  • Susheel Chandradhas November 25, 2008 05:13 am

    Love this... Unfortunately where I live, the sky goes pink every night... I'd have to drive out about 2-3 hours before I can get a dark sky. Very likely that it's worth the trouble.

  • Tami November 21, 2008 05:23 am

    Great article. I'd love to see the post on image stacking in Photoshop too.

  • Patrick Anderson November 21, 2008 05:07 am

    I've been fascinated with star trails since I was a boy - saw my first in one of those old "Time-Life" nature books.

    I read about a similar technique in Sky & Telescope magazine a number of years ago. I would love to do these more often.

    Here's an example I shot earlier this summer at Devil's Tower in Wyoming.


    Thanks for posting this - I love to see how others accomplish this!


  • evan johnson November 20, 2008 08:29 pm

    I've been doing a lot of long exposure shots lately and have the star swirl shot on my list but I'm procrastinating and keep moving it down the list.

    Thanks for the article though, very helpful.


    - Evan

  • Chris Luckhardt November 18, 2008 02:48 pm

    Great article and thanks for using my photo (the last one, credited to "motionblur").

    I would like to clarify that my image is a single shot without the use of stacking software. I did use Noise Ninja to clean up the image a bit. For the record, I used my old Rebel XT body, the exposure time was 771 seconds, an aperture of F/3.5, 200 IS) and my 28-135mm lens, set wide and using the infinity setting.

    All of my star trails photos are single exposure images. At one time I had considered the stacking technique, but once I purchased the Rebel XTi, I found there was no need, thanks to its mostly noise free captures.

    For another example, using my Rebel XTi in a single capture with *no* Photoshopping, please see this image: http://flickr.com/photos/motionblur/2476300145/

  • batman November 18, 2008 07:37 am

    this is great - just what i've been looking for.

    keep it up - ill be keeping tabs.

    kind regards

  • Suzanne November 18, 2008 07:08 am

    Just Amazing. I was living in San Diego so getting away from the lights was difficult. I now live in northwest Montana in the mountains, just rural enough. Tonight I'll try it. Simple instructions, just like I need. Will keep you posted. Thanks!!!!

  • Ross Goodman November 18, 2008 06:20 am

    I managed to get this shot:

    the other night using my Nikon P5100.
    I used the software provided here : http://startrails.de/


  • kimrose November 18, 2008 03:22 am

    Very interesting! Came about 2 days to late though :P I went out to the desert and took some star photos Sat. night and they came out pretty awful... At least I learned something from this article and now I want to go try it again!

    Question... how long should you wait between shots? Like if you have a longer exposure... and how much does this kill the battery?

  • Will November 18, 2008 01:55 am

    Great article... this is a very useful technique. It is certainly less risky than a single exposure star trail. Having said that, we managed to take this photo using a single 40 minute exposure with a 1ds mkIII. We used a single exposure because a lot of photo competetions do not allow composite images.


  • Rahul November 18, 2008 01:10 am

    Anyone know of any freeware image stacking software? Thanks.

  • James November 18, 2008 12:52 am

    Thanks, nice article