Ever since the first time I looked in a book with long-exposure photography, I’ve loved the look of trailing stars in photographs. The idea is simple, expose for a long enough period of time to record the rotation of the stars as the Earth spins. My own attempts were never very successful using film due to the negative effects of reciprocity and my lack of technical skills and patience. Even later, when I finally got a digital SLR camera with the battery life to pull off an hour long exposure, my star streak photos were always sub par, riddled with technical and aesthetic problems. One of my problems was that I always tried to shoot star streaks as if I were shooting a film camera: One very long, guessed exposure, teetering on the edge of my battery life. As I will outline, there are many problems with this technique and there is a much better solution!

Stars over Lake Tahoe

The “Traditional” Method of Getting Star Streak Photographs

Things used to seem quite simple. Find a dark sky without too much light pollution, calculate an exposure based on the ISO, working aperture and phase of the moon, place your camera on “bulb” mode and expose for a long enough period of time so that the stars streak through the sky as the Earth rotates. As simple as this seems, there are many problems with this method. For one, while digital cameras don’t have the issue of reciprocity like film does, they do have the inherent problem of noise. Without getting too technical, all digital cameras use an internal imaging device to convert light into an electric charge, this is either a CCD or a CMOS in most cases. As the camera exposes, and depending on the ambient temperature, the sensor begins to heat up and produce thermal noise or dark current. Here, the star detail is limited because I exposed for the foregroundThis can heavily degrade the detail and quality of an image. Most modern digital SLRs have built in long exposure noise reduction by silently taking second “dark frame” for the same length of the first, thus removing the dark current. One of the major problems with the built in noise reduction is that in order to be effective, the camera has to noise reduce under the same ambient temperature as the original exposure(meaning the photographer has to stay on location for twice the amount of time), the other problem is battery life limitations. With my older Nikon D200 + battery grip, I could pull off about an hour of exposure + an hour of noise reduction and just barely have juice to preview the final shot.

Another problem with the so called “Traditional” method is balancing a light polluted sky with the foreground. Unless you are just going for a shot of the stars in the sky and don’t care about any foreground detail, you are most likely going to be very frustrated when you find that the sky is too bright to make out the stars due to light pollution if exposing for foreground detail (see the photo on the left). City lights, car headlights and especially a large phase moon can light up the sky dramatically brighter than the foreground leaving you with the choice of either underexposure your foreground, or losing precious star detail and contrast by exposing for foreground detail. Painting the foreground with light is one solution, but doesn’t solve the other problems.

Stacking, the (Almost) Perfect Solution!Stars over Verdi, NV

So instead of shooting a single long exposure, we can take a large number of short exposures equaling the length of time that our single long exposure would have been and “stack” them together. Let me clarify. Lets say you would like to have an hour long exposure of the stars moving across the sky. You could set up and shoot an hour long single exposure and run in to the previously mentioned problems, or instead you could do the following…

Shooting:

  1. You’ll need a fully charged battery (battery grip is recommended), a cable release or remote, a tripod and a memory card capable of holding a few hundred shots.
  2. Set your quality to .jpg-fine or RAW (Keep in mind that if you want to shoot raw, you will have to batch process a large number of files).
  3. On a tripod, compose your shot and set your shutter speed to the slowest speed your camera will shoot continuously, most digital SLRs will shoot as slow as 30 seconds, don’t use bulb.
  4. Taking a few test exposures, set your exposure (using your ISO and aperture) so that you can see stars in the sky. Don’t overexpose the sky, we want a fairly dark histogram, with a very small spike near the right for the stars. Also, don’t worry about getting too much foreground detail in your exposure right now, just focus on the stars.
  5. Set your white-balance for the sky. This is a matter of personal preference and it will vary depending on the light pollution.
  6. Turn off any kind of long-exposure noise reduction that is built in to your camera. High ISO NR can be left on.
  7. Set your camera to continuous drive mode.
  8. Lock your cable release/remote so that the camera is stuck firing continuously. Now the camera will shoot one 30 second exposure after another until you stop it.
  9. Stop after an hour (or however long your predetermined exposure is). The longer you let the camera shoot, the more the earth will rotate and the longer the star streaks. Also, keep an eye on the camera as some cameras do not have the buffer to handle so many shots in a row.
  10. Don’t move the camera! Once you’re done exposing, you still need to shoot a manual dark frame for noise reduction. Put your lens cap on, make sure the viewfinder doesn’t have any light shining into it and expose for 30 seconds.
  11. The last thing you need to do it shoot a brighter foreground frame for the detail in the foreground. Put your camera on bulb, and make an exposure long enough to get good detail in the foreground, don’t worry about overexposing the sky. I recommend using the same aperture and ISO setting as the 30 second exposures for noise consistency. You can enable in camera long exposure noise reduction for this if you want, or you can shoot another dark frame with the lens cap on of the same length for noise reduction. I recommend turning NR back on for this if you have the time/battery life.
  12. Go home and follow the next section for processing.

Processing:
Stacking How To

Windows Users:
Note that Windows users can also follow the OSX instructions for a bit more work, but also a little more control.

  1. Download StarTrails from HERE. We will also be using Adobe Photoshop CS3 (although you can probably use CS2 or even Elements 6).
  2. Open StarTrails and go to File –> “Open Images” and select all of the frames except for the dark frame and foreground frame.
  3. Go to File —> “Open Dark Frames” and select your darkframe
  4. Click Build —> Star Trails and give it a few minutes. You can watch as the star streaks grow.
  5. Save as a .tiff file and open the .tiff in Photoshop
  6. Also open the foreground exposure jpeg and paste it as a new layer on top of your stacked .tiff file in photoshop
  7. Create a black mask on the foreground layer and paint in the foreground carefully (see graphic above for example).
  8. Apply curves, noise reduction and other editing adjustments and your done!

OSX Users:

Since the StarTrails Software doesn’t work in OSX, we can use Photoshop to do the same thing. Its a bit more work, but it gives you more individual frame control. There are two ways to do it:

Method 1: Use the CS3 script under File —> Scripts —> “Load Files into Stack.” Open all of your exposures except the foreground frame. Change each layer’s blending type to “lighten” and the dark frame’s to “difference.” This is time consuming and tedious. I recommend method 2.

Method 2: Download this Photoshop action (this does everything above automatically, except the dark and foreground frames). Follow the directions on the site (one step). I recommend deleting the action step where it flattens the layers. Then add your dark frame as a new layer, change the blend type to difference. Next add your foreground image as a layer, create a black mask and paint in the foreground. Apply curves, noise reduction and other adjustments as needed.

Train Bridge Streaks

Almost Perfect? What gives?

While the stacking technique gives you a ton of control, it is definitely more work. Also, at large print sizes, small gaps can appear in the star streaks from the small gaps between exposures.

Some Tips

  • You can include the polar axis (rotational center) in your shot by including Polaris (the North star) in your photo (see the Tahoe photo at the top of this post)
  • Shoot during a new moon or smaller than half phase if possible
  • Look up local moon rise/moon set times so the rising moon doesn’t mess you up in the middle of an exposure
  • If you have a large budget, look at battery grips and/or external power sources for your camera such as Quantum’s Turbo 2×2 battery

Timelapses

If you took a bunch of stacking photos, you can always put them together as a time lapse like this:

That’s it for now, feel free to comment or contact me with any questions.

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87 Comments

  1. Arjen Mulder
    on August 18th, 2010
    1

    Hi Dan,

    Very helpful article, just did my first experiments with star streaking in Spain and there is lots of room for improvement.

    Question: if I would only wanna make one shot of let’s say 1 hour, could I reduce noise by making a black shot directly after it, also of one hour, instead of using the in-camera noise reduction? Would that save battery power? I don’t want to do the whole stacking thing but gotta reduce noise of course.

    Thanks for sharing your thoughts on this with me.

    Cheers,
    Arjen

  2. Nathan
    on September 6th, 2010
    2

    Will a Nikon D3000 be able to handle the 30 second exposure one after another for an hour? What happens if it can’t handle it?

  3. Randall Jackson
    on November 8th, 2010
    3

    I have a Nikon D700 and I’m wondering how long of an exposure could it handle? Related, would multiple exposures be a better way to do this?

  4. Chapter 6 Assignment 2 Photoshop
    on November 9th, 2010
    4

    […] me start off my linking to the master of all star trails Dan Newton and his amazing tutorial on star trail shooting. His tutorial is the first time I tried stacking with my star trail […]

  5. Inspiration – Light Painting « Richie | Photography
    on December 30th, 2010
    5

    […] trails. There is obviously a little more to it than that. You can read all about it on his blog: http://www.liquidinplastic.com/2008/06/startrails/ There are loads of other cool examples of light painting on […]

  6. Markus
    on January 6th, 2011
    6

    hi dan. i made it with the olympus E-5 with 12-60mm at Iso 400 2,8 / 30sec. the picture are perfect, very low noise.
    a add the pictures to imovie with 0,1 sec per picture, and the ouput ist very bad ! i have Lighthing noise in “slices”, do you know what i mean ? any idea ?

  7. Max
    on April 20th, 2011
    7

    Hey Dan!

    Great read!
    If anyone’s interested I found a star stacking program
    for max osx users called “StarStax”.
    You can find it here:

    http://www.markus-enzweiler.de/StarStaX/StarStaX.html

    Happy shooting
    Max

  8. Star trail | Ole Faass Photography
    on May 27th, 2011
    8

    […] Tevens kun je meer info vinden op deze site: http://www.liquidinplastic.com/2008/06/startrails/ […]

  9. Aaron
    on June 1st, 2011
    9

    Dan,

    Thank you for putting the how to page on your site, it made my first attempt of a city skyline startrail so easy to do. I never thought it would be possible to do such a startrail with a major city bridge in the foreground. I put the most southern star over the top of the bridge and it has worked a treat… The photo is of the Story Bridge in Brisbane, Australia.

  10. Karim
    on June 2nd, 2011
    10

    Thanks for sharing and giving inspiration!
    It’s a A-Z and very helpfull guide!

    What I always thought to be near impossible or only for the top photgraphers with very expensive equipment is now also for me.

    Still enough for me to learn, but because of your guide, it’s made possible to start and keep on trying.

    Again, thanks for sharing, and the website is full of usefull info and some really stunning photo’s.
    Always looking forward to see more guides and photo’s of your work ofcourse.

    Regards,
    Karim (the Netherlands)

  11. Chris Dougherty
    on June 11th, 2011
    11

    How is it that one might animate the light trails with no light decay (permanent streaks) in stacks, in PS CS5?
    Thanks,
    CD

  12. adam tan
    on June 22nd, 2011
    12

    Thanks for the generous sharing, dan!
    your works are brilliant!

  13. Syd
    on June 24th, 2011
    13

    Thanks, that has helped a lot for individual still shots. It lead me to a question that I have not managed to find an answer for.

    I was watching your video “Nevada Nights” on You Tube and noticed that when the star trails start they build up a trail that decays after a set length.

    How does that happen? Most other vids end up with a bunch of circles that spoil the effect.

    Regards,
    Syd

  14. Tom Moulin
    on September 2nd, 2011
    14

    Thanks for the sick beta!

    Headed out to give it a whirl

  15. How to Photograph Star Trails with a Digital SLR (+ Video!) | The Nomadic Photographer
    on September 13th, 2011
    15

    […] known as “Stacking”.  Dan Newton of Liquid In Plastic has written an excellent post HERE on how to photograph star trails using the stacking technique.  I suggest you read it before […]

  16. Lucas Boland
    on October 4th, 2011
    16

    Thank you Dan for putting together this post. I found your site through a Google search and am glad I did. However, I’m a bit confused and about how to lock the camera if it’s not in Bulb/Time mode. I have a d5000 with the ML-L3 wireless remote. Previously I had done star trails (with mixed results) using Time mode. The remote has a maximum exposure time of 30 minutes and there is just way too much light pollution around me. After reading your article I’m incredibly excited to try stacking but cannot for the life of me figure out how to “lock” the camera in continuous release mode without going back to the Time setting. Does the wired MC-DC2 operate differently that there is a locking feature? Or is this a feature not available in the d5000? What am I missing???

  17. Dan Newton
    on October 4th, 2011
    17

    Lucas, if you get the MC-DC2 (or an off-brand alternative), you can put your camera on continuous shooting mode, set the exposure to 30-seconds and there is a “lock” on the remote that is the equivalent of holding down the shutter release button. I don’t think that you can do this with the ML-L3 except for bulb mode. I hope that helps.

    -Dan

  18. Lucas Boland
    on October 4th, 2011
    18

    Thank you! I knew it had to be something simple but I’ve been trying to find an answer for three days and came up with nothing. I’m ordering right now and can’t tell you how excited I am to trying a new method for trails and for light painting. Again, your help and post are both very appreciated. I’ve subscribed to your RSS and look forward to digging into your website!

  19. Mark Connick
    on October 8th, 2011
    19

    Hi Dan,
    Thank you very much for this great guide. Really well put together and great images. I’m now ready to give it a go.
    Much appreciated.
    Regards.
    Mark

  20. Martin Sutcliffe
    on November 11th, 2011
    20

    Dan, great stuff. As you mentioned gaps can appear at larger print sizes and I am finding this happens at not so large sizes. I suspect this is due to the delay between shots which seems to be caused by buffering issues. Is there a way to overcome this? A fast card doesn’t seem to make much difference/ My camera is Nikon D300.

  21. Harsh
    on December 22nd, 2011
    21

    Hi Dan,
    Great Article! I was wondering if I can use the stacking technique with my Nikon D3100 ?

  22. Bob Hamers
    on December 24th, 2011
    22

    Hi Dan,

    Thanks for the great tutorial. I was amazed with the pictures and just needed to try it for myself. I just cant seem to get rid of one problem. Even if the camera is in continuous drive mode, I keep getting small gaps in the star trails. I guess this is just due to the delay caused by the shutter cycle. How do you deal with it in post-processing?

    Regards,
    Bob

  23. Star Trails – Tricks to the Trade | 366 Project - 2012
    on January 20th, 2012
    23

    […] This tutorial was taken from: http://www.liquidinplastic.com/2008/06/startrails/ […]

  24. Doug Bibo
    on March 11th, 2012
    24

    Dan,
    Very nice write up. I do star points, star trails, and star point time lapses. What I don’t get is the star trail timelapse, where the stars have tails, suggesting a lot more movement. I don’t get how that’s done. Is that a software thing?

    Thanks,
    Doug

  25. Star Trails – A Short Tutorial | 366 Project - 2012
    on May 9th, 2012
    25

    […] more information on star trails, a more detailed explanation, and some wonderful tips go to: http://www.liquidinplastic.com/2008/06/startrails/ and read Dan Newton’s […]

  26. The Courage to Create « Janyaa's Scrapbook
    on May 20th, 2012
    26

    […] this post is copyrighted by Dan Newton. I highly recommend you checking out his gallery and blog, Liquid In Plastic! Share this:TwitterFacebookLike this:LikeBe the first to like this […]

  27. Kenneth
    on July 13th, 2012
    27

    Great work!

    I’m trying to figure out how to do the effect 20 seconds into your video: http://www.youtube.com/watch?v=oLd1gpVa5TY

    Is there a special script to stack only about 30 frames at a time?

    Thanks!
    Kenneth

  28. gary
    on September 17th, 2012
    28

    Hi, first off, fantastic work. i love your video !! which is the main reason for this question ? what software are you using to do the star “trail” timelaps ? any help qould be most welcome :) again great work and thanks for your time.

    Regards
    Gary.

  29. gary
    on September 17th, 2012
    29

    Hi, first off, fantastic work. i love your video !! which is the main reason for this question ? what software are you using to do the star “trail” timelaps ? any help would be most welcome :) again great work and thanks for your time.

    Regards
    Gary.

  30. Dan
    on September 28th, 2012
    30

    Very cool. I have heard about stacking before, but never thought to try it. Always leaned towards long exposure. Curious though, what film were you using? Fuji Velvia transparency has one of the lowest reciprocity failures… dont (passively) diss film. :)

  31. Experiments with Time Lapse » Starlit Vision
    on October 16th, 2012
    31

    […] composite image.  I’m no expert in combining image so take a look at the articles here: Guide to Star Trails and How to Photograph Star […]

  32. Astrophotography questions
    on December 12th, 2012
    32

    […] available. I just find that the wider the better in this scenario. Thanks everyone! Try here – Lets Go Streaking, a Guide to Star Trails : Liquid in Plastic – Photography and Words by Dan N… Scott H Murray D800 / D80 + Lenses Reply   Reply With […]

  33. North Star Long Exposure Help?
    on May 30th, 2013
    33

    […] if you do shorter exposures, you can have a better feel for how it's going to turn out. Here's a link to the tutorial where I learned how to do the stacked method. It might take you a few tries, but in […]

  34. Dan
    on October 14th, 2013
    34

    Dan,
    Loved the video with the timelapse and still pics. Also have the same question as another asked. I didn’t see a response.

    How do you do the time lapse where the star trails look like comets streaking across the sky?

    Paul

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