Multicoloured Star Trails
Multicoloured Star Trails Photography in ZERO Light Pollution
Singalila Ridge, Nepal
There’s something about photographing star trails that just feels magical. Watching the stars seemingly “move” across the sky is mesmerizing, and it’s no wonder that this type of photography is so popular.
Star Trails are the result of taking very long exposures of the stars in the night sky. The camera shutter is left open for an extended period of time in order to capture the apparent motion of the stars as they move across the night sky. Because of the Earth’s rotation, from our perspective, the stars appear to be moving across the sky, offering us the possibility of capturing streaks of light. Here, the longer the exposure, the longer the trails. The length and shape of the trails will depend on the length of the exposure and the direction of the camera. The great thing about photographing stars is that, unlike deep space astrophotography, it doesn’t require specialized equipment like star trackers and/or telescopes to achieve phenomenal results. Any DSLR or mirrorless camera with a wide-angle or even telephoto lens, a sturdy tripod, a remote shutter trigger or intervalometer and a big enough memory card is all that is required.
There are two main styles of star trail photography: Circumpolar Star Trails or Star Circles and Star Lines. Star Circles are star trails that form concentric circles around the north or south pole star. Star circles are created by photographing stars in the north or south direction. This is because the star trails will appear to rotate around the north or south star, depending on which hemisphere you’re in. Star lines are an effect where the star trails appear to streak in a fairly straight line across the sky. Star lines are created by photographing stars in the east or west direction. This is because the Earth’s rotation causes the stars to appear to move across the sky from east to west. So whether the photograph achieves star trails that are lines or concentric circles simply depends on which hemisphere they’ve been photographed in and in the direction the camera was aimed.
In the last week of February 2025, in collaboration with HyTiCos, I had the opportunity to explore some areas in Telangana which could be leveraged as dark skies for star gazing and astro photography. The first location is near the town of Nirmal - a Bortle 4 sky with some degree of light pollution. This location in the district of Nirmal has spectacular naked eye visibility of some of the major constellations and star clusters as you can see in the timelapse. At about 18 minutes past midnight we were also blessed by a brilliant meteor which lit up the sky for a split second. It was captured on a single frame of my timelapse and I have included that in this video. The sky was brightened for that split second by the light from the falling meteor.
But that was only one meteor we saw. In total 9 separate meteors were captured in the timelapse throughout the night which I have composited into a single image with the Milky Way. Coincidentally it was also a waning crescent Moon at 4% and less which made the conditions irresistible.
But today is about shooting under Bortle 1 skies - Zero Light Pollution!!!
A clear sky is one of the most important things to watch for when planning a Star Trails photo. In order to get a spectacular Star Trails image, ideally a completely clear sky for the entire duration of the shoot is preferred. I would recommend using Dark Site Finder to help pick a good location. The great thing about star trails is that you do not need a dark sky to get a beautiful image. Even in light polluted areas, you can still capture a great star trails photo. You can also do star trails image during a full moon.
For insights into how star trails or even Milky Way photos look from Light Polluted skies click on the links below to read more.
Star Lines or Star Paths
Exif: Canon 1Dx Mark ii | EF100-400mm f4.5-5.6L IS II USM @ 100mm | f/4.5 | 25 seconds | ISO 800 | Manually focused with a Bahtinov Mask & WB set to Manual at 3800k.
Timelapse Start: 19:12:06 | Timelapse End: 03:43:00 | Total Duration of shoot: ~ 08 hours 30 minutes | 1180 images stacked with StarStaX and processed in LightRoom.
Temperature on the night of 23 March when I recorded the Circumpolar Star Trails.
35% Last Quarter of the Moon on the night of 23 March. The moon did not rise till well past 2am on the 24th.
Zero Light Pollution at Tumling
The colours in the light pollution map above are explained via the Bortle Scale chart below. My location this time was a Bortle 1 with the only deterrent being the weather as I was fogged out completely for the second half of my trip on all nights. Some time in the future I hope to make some more trips and head further North - deeper into the forests and mountains. I am told there are some pristine locations which make ideal locations for star gazing and astro photography including deep space astrophotography.
The Bortle dark-sky scale (usually referred to as simply the Bortle scale) is a nine-level numeric scale that measures the night sky's brightness of a particular location. It quantifies the astronomical observability of celestial objects and the interference caused by light pollution.
Circumpolar Star Trails
Circumpolar stars always reside above the horizon, and for that reason, never rise nor set. All the stars at the Earth’s North Pole and South Pole are circumpolar. Meanwhile, no star is circumpolar at the equator. Anyplace else has some circumpolar stars and some stars that rise and set daily. The closer you are to either the North or South Pole, the greater the circle of circumpolar stars. The closer you are to the equator, the smaller the circle.
The Big Dipper and the W-shaped constellation Cassiopeia circle around Polaris, the North Star. They do so in a period of 23 hours and 56 minutes. The Big Dipper is circumpolar at 41 degrees North latitude and all latitudes farther north. Image via Sazvežda – Page/ Ana Oriflame/ Pinterest.
From the Northern Hemisphere, all the stars in the sky go full circle around the north celestial pole once a day. Or, more precisely, go full circle every 23 hours and 56 minutes. And from the Southern Hemisphere, all the stars in the sky go full circle around the south celestial pole in 23 hours and 56 minutes.
We in the Northern Hemisphere are particularly lucky to have Polaris. It is a moderately bright star, closely marking the north celestial pole. The north celestial pole is the point of sky that’s at zenith (directly overhead) at the Earth’s North Pole. For centuries, Polaris—the North Star—has been our guiding light, an unshaken beacon in the northern sky. But is it truly motionless? The truth is far more mysterious. Polaris does move, tracing a small, ghostly circle every night. And in time... it will be replaced.
At the equator (0 degrees latitude), the star Polaris – the current stellar hub – sits right on the northern horizon. Therefore, no star can be circumpolar at the Earth’s equator. But at the North Pole (90 degrees), Polaris shines at zenith (directly overhead). So from the North Pole, every star in the sky stays above the horizon all day long every day of the year.
Our latitude determines the circle of circumpolar stars in the sky we see. For instance, at 30 degrees North latitude, the circle of stars within a radius of 30 degrees from Polaris is circumpolar. In the same vein, at 45 degrees or 60 degrees North latitude, the circle of stars within 45 degrees or 60 degrees of Polaris, respectively, would be circumpolar. Finally, at the North Pole, the circle of stars all the way to the horizon is circumpolar. Tumling is located at 27.0315° N, 88.0689° E.
At 41 degrees North latitude and all latitudes farther north, the famous Big Dipper asterism is circumpolar. That’s because the southernmost star of the Big Dipper, Alkaid – the star marking the end of the Big Dipper handle – is 41 degrees south of the north celestial pole (or 49 degrees north of the celestial equator). Bottom line: Circumpolar stars are those that never rise nor set from a certain location. At the poles, all stars are circumpolar, while at the equator, no star is.
Star Lines or Star Paths
Star Lines or Star Paths, in contrast to Circumpolar Star Trails, can be photographed when the perspective is shifted to either East or West. The Star Trails or Star Paths appear to be straighter rather than circular. Star Lines are a lot easier to shoot because there is no need to find Polaris or the South Celestial Pole and they are more common the closer one is to the Equator.
Circumpolar Star Trails/ Star Circles/ Star Arcs
Exif: Canon 1Dx Mark ii | Sigma 50mm f1.4 DG HSM ART @ 50mm | f/2.8 | 19 seconds | ISO 500 | Manually focused with a Bahtinov Mask & WB set to Manual at 3800k.
Timelapse Start: 19:49:10 | Timelapse End: 01:50:43 | Total Duration of shoot: ~ 06 hours 1 minute | 1034 images stacked with StarStaX and processed in LightRoom.
Single vs Multiple Exposure Star Trails
Star Trail images can be shot with either a single long exposure or by stacking multiple shorter exposures. The two methods can give very different results, and each method has its own advantages and disadvantages.
One of the biggest advantages of shooting a single long exposure is the reduced processing time compared to stacking. The RAW image can be loaded in LightRoom and processed immediately avoiding the time consuming steps of cleaning/stacking/blending multiple exposures. When shooting a single exposure, the exposure settings are determined by the amount of light pollution in the shot. For most instances the light pollution on the horizon is almost always over exposed to the point that it can’t be saved in post. An example of this can be seen in my Star Trail images from Nirmal. In such instances most photographers would usually take a few test images or sometimes take a few blue hour images which can later be blended over the star trails image.
But a single long or ultra long exposure can be ruined by things like the headlights of a distant car passing through the shot, or a wayward flash light. In my timelapse from Nirmal the headlights of a distant car are clearly visible as it takes a turn almost two kilometers away. But in a stacked image this can be handled quite easily. Even in this timelapse of the 50mm star trails, there is some light leak at the beginning of the timelapse as a few Land Rovers came in to roost for the night. But as the timelapse progresses this light eventually disappears. I have intentionally retained these light leaks as an illustration of the problem light pollution creates.
In the second half of the timelapse when I was shooting with the 100mm, I had positioned my camera at some elevation from the ground and the lights from the houses nearby illuminated the tree line in the foreground and bottom half of the frame. But again as the night progressed and people went to bed for the night they turned off these lights and the foreground gradually darkened and the illumination from the stars took over. Towards the end of the 100mm timelapse the Moon also starts to rise from the bottom right of the frame illuminating the fog and making it seem like noise in the frame.
There are other issues that can arise, for example dew forming on the lens towards the end of the shoot - this happened during my Milky Way timelapse which I will talk about in my next blog, or fog and clouds moving in during the shoot. Both of these can ruin a single exposure image but if it happens with a stacked sequence you could just discard those images or persist with the shoot and the fog and clouds will eventually move away. This will be clearly illustrated in my next blog post of the Milky Way rising over Jaubari. For this shoot I was expecting fog and used a lens warmer to ensure that the front element of the lens stayed clear for the duration of the shoot.
Stacking Multiple Exposures
Stacking is my preferred method, as it allows me to capture lots of stars and have very long trails, and I have a lot more control over the exposure of all the elements in the image such as stars, empty areas of the sky, landscape and light pollution. If I encounter any of the issues mentioned in the single exposure section above they can be dealt with relatively easily. Stacking also gives me the flexibility to choose my shutter speed and intervals. For example, in the 50mm time lapse my shutter speed was 19 seconds giving me pinpoint stars which can easily become a timelapse on their own and also showcase any meteors which may have come through the frame. This technique of using the correct shutter speed for pinpoint stars is illustrated clearly in this photo of the Milky Way rising over Nirmal and multiple meteors shooting through the frame throughout the duration of the shoot.
Fun Fact: On average, more than 17 meteors of different sizes and shapes, hit the Earth every day. There are quite a few more which don’t hit and burn out in the atmosphere. In the timelapses here you can easily see a few meteors that graced the skies on the nights I photographed these trails.
The downside to this method is the time spent in post. The image stacks you see above took about 3-4 hours to edit (cleaning plane trails and hot pixels, stacking stars and final editing). Stacking also gives you the option of tapering off the ends of the trails using the ‘comet fade’ effect, or blending in a twilight image for better lighting on the landscape parts of the image. This is my preferred way of stacking my star trails as I like the gradual fade of the star trails as they move through the frame. There’s also the option of doing something in between the two methods, stacking a small number of longer exposures to give the look of the single exposure method but with longer trails. Programs like StarStaX have multiple options to choose from creating very different star trails.
But those details are for the next blog. For now let us return to the final timelapse video of both the 50mm and 100mm star trails including the final stacked and processed images.
For the Timelapse I used my Canon 1Dx Mark ii paired with two lenses: the Sigma 50mm f1.4 DG HSM Art and the EF100-400mm f/4.5-5.6L IS II USM. The camera was perched on my ProMediaGear sticks and the BH-55 Ball Head and I have not used any Night or Light Pollution filters as there was no Light Pollution.
For Timelapse 1:
Exif: Canon 1Dx Mark ii | Sigma 50mm f1.4 DG HSM Art @ 50mm | f/2.8 | 19 seconds | ISO 500 | Manually focused with a Bahtinov Mask & WB set to Manual at 3800k.
Timelapse Start: 19:49:10 | Timelapse End: 01:50:43 | Total Duration of shoot: ~ 06 hours 1 minute | 1034 images stacked with StarStaX and processed in LightRoom.
For Timelapse 2:
Exif: Canon 1Dx Mark ii | EF100-400mm f/4.5-5.6L IS II USM @ 100mm | f/4.5 | 25 seconds | ISO 800 | Manually focused with a Bahtinov Mask & WB set to Manual at 3800k.
Timelapse Start: 19:12:06 | Timelapse End: 03:43:00 | Total Duration of shoot: ~ 08 hours 30 minutes | 1180 images stacked with StarStaX and processed in LightRoom.
Audio Recording Equipment: Zoom H1N | Roland CS-10EM Binaural Microphones & Earphones | SwitchPod Handheld Mini Tripod. All the wind sounds you hear within the timelapse - with the exception of the background music - is recorded at the site as the timelapse was being shot.
Find everything I have used in my Kit Bag.
Photographing & Creating a Star Trails Timelapse
A clear sky is one of the most important things to watch for when planning a Star Trails photo. In order to get a spectacular Star Trails image, you should try on a completely clear sky for the duration of the shoot. I would highly recommend using Clear Outside charts to help pick a good night. These charts can be a bit difficult to understand at first glance but basically, the more rows of dark blue squares, the better. Once the weather is sorted, I typically switch over to PhotoPills to start planning and work out what I can include in my frame with some help from Google Maps - and the PhotoPills Academy has some amazing tutorials for beginners and advanced shooters along with a ton of very useful tools. Another awesome app is THE PHOTOGRAPHER'S EPHEMERIS which also provides numerous resources and tools to help plan the shoot. Both PhotoPills and TPE are excellent.
The best thing about photographing star trails is that you do not need a dark sky to get a beautiful image. Even in light polluted areas such as this, great star trails can still be captured. Star Trails images are also possible during a full moon.
Timelapses can be created using almost any camera and off late most recent DSLR/mirrorless cameras have a "time-lapse mode" which allows one to create a time-lapse very easily without any editing. Once activated, one just has to point the camera to the the Milky Way, focus, and launch! Me - I prefer the old fashioned way because it gives me more control and especially over the flicker.
Capturing star trails or timelapses for that matter doesn't require expensive gear. All you need is a camera with an intervalometer and a wide angle lens. Any wide angle lens will do, even ones that have bad coma. Since all exposures will be blended, the star distortion is not an issue. Personally, I would recommend using a Full-Frame camera with a 14mm lens. This allows a large portion of the sky with a foreground to be captured. Alternatively, the camera can be set to capture 90% sky for the star trails photos and for the foreground, take 1 photo at the beginning or end of the shoot and these two exposures can be blended in programs like Photoshop. I personally avoid all the software gimmickry and shoot what I want and how I want in camera and at the location unless I am tracking the Milky Way.
If your camera does not have a built in intervalometer, you will need to purchase a remote that has this capability. I use a few triggers which you can find in my Kit Bag - Accessories.
Of course, you'll also need a sturdy tripod and ballhead to make sure the camera does not move over the hours. I have listed what I typically use below:
A wide angle or a telephoto lens which will give a nice wide field of view.
An intervalometer which will help to control the intervals and exposure times. Some modern cameras have built-in intervalometers but I think an external one still provides more flexibility.
A sturdy tripod which is self explanatory as you need a stable base and avoid any shake caused by wind or uneven ground.
A Ball Head to get to the angle required.
Finally a star tracker which will allow to create a Timelapse that follows the Milky Way and will show the rotation of the earth. This, however, is not mandatory but a good to have.
A large, fast memory card is also recommended as timelapses involve shooting potentially hundreds of Long Exposure photographs one-after-the-other for up to 6 hours straight or even longer as in this case! We cannot afford to have our memory Card get bogged down, as it will completely mess up the interval. I prefer the Prograde CFast™ 2.0 Cards. These are high performance cards with blazing read and write speeds verified to perform at a sustained read rate of up to 550MB/second and a sustained write speed of up to 450MB/second. And thankfully they have never failed me yet on any of my expeditions - be it wildlife or landscape or astrophotography. I also have a few spare Lexar and Sandisk cards of similar sizes and speeds as a fail-safe.
Pro Tip: Direction is not important for Star Trails photography because different trails are possible in different directions. There are two main types of star trails: Circumpolar Star Trails or Star Circles or Star Arcs and Star Lines or Star Paths. Photographing one or the other will depend on the direction in which you’re pointing your camera.
STAR CIRCLES
Depending on the hemisphere you are in, point the camera directly north or directly south at either of the celestial poles and you’ll see the stars moving in a circular motion - creating either circles or arcs. These are the so-called star circles, better known as Circumpolar Star Trails. They are the most typical star-trail photography subjects
STAR LINES or STAR PATHS
On the other hand, when you shift your perspective and look towards the east, or west, you’ll start seeing straighter star paths instead of circles. Star paths can be easier to shoot because you don’t need to find Polaris or the south celestial pole. If you are located near the equator, star path photos are more common than taking star circles images.
Camera Settings
First and foremost - there are no “default“ settings when photographing Star Trails. But ideally before starting to photograph the star trails, one will need to decide the look of the final image - whether to have tons of stars in the image creating dense and bright star trails or to have fewer stars, more star colours and some spacing between them. Shooting at an ISO of 1600 or higher, as I have done here, will create fairly dense trails but they will not be as colourful or vibrant as shooting between ISO 400 and ISO 1000. I am headed out to the Singalila Ridge for a week next week and weather permitting I hope to shoot some low ISO vibrant star trails hopefully with an interesting foreground subject like the Kagnchendzonga range or some of the stunning monasteries that dot the landscape or even light paint a rhododendron tree. Now THAT is something to look forward to.
With that said, here are some preferred settings to get you started:
Always shoot in Manual
Focus on the stars Manually. Turn of Auto Focus. Turn of Lens Stabilization.
Preferred Aperture: f/2.8 or f/4 or the lowest possible aperture
Preferred ISO: Between 400 and 1000 (the maximum ISO I have used is ISO 3200 but this has always depended on the ambient light pollution)
Shutter Speeds: Between 20 -30 seconds (I usually try and keep within the sharp stars limit so I can have both a timelapse and if a meteor goes through I can have a single photo with sharp stars and the meteor streaking through it. I used 19 second and 25 second shutter speeds in this case.)
White Balance: Between 3000 - 5200 Kelvin (Please DO NOT leave on Auto)
Long Exposure Noise Reduction - OFF
Many people recommend using ISO 1600+ when shooting at night. However, this has the potential to clip the highlights (stars in this case). Since our entire image is focused on the stars, this isn't a good idea! You might be surprised at the star colors you can capture when you use a lower ISO. If you use a substantially lower ISO, you could also take longer exposures. Instead of taking 20 - 30 second images, you could take 1 or even 2 minute exposures! These longer exposures would capture more light, resulting in a cleaner image, with less grain. It doesn't matter that the stars will show motion in each photo, we are creating a star trails image after all.
The best part of star trails photography is the amount of flexibility it provides. A number of different techniques can be used and each will always result in a great final image. A word of caution though - be aware of the interval between the individual photos. If the interval is not set properly it will lead to some serious issues while creating the timelapse. Always set the shooting interval to one second longer than the shutter speed.
However some camera brands are programmed differently, and they require a 1 Second interval. Therefore, if the shutter Speed was 20 seconds, the interval would simply be 1 second. If a 21 second interval is used in this case, it would result in a large gap between each photo. Therefore before heading out for the night, determine which way the camera works! The interval will either be 1 second longer than the shutter speed, or just 1 second. Try both options and see what happens. If the camera goes "click..click" it indicates that the exposure ended and another one began. If only one "click" is heard and then a long pause, the interval isn’t set properly.
Now all is set and the only thing needed is spending the hours needed to get the photos. The more the number of exposures, the longer the star trails will look. In this current scenario I took approximately 2300 photos over almost 12 hours.
If you don't want to spend all night for one star trails image, there's a much faster way - use a telephoto lens! As you zoom in on the stars, their apparent movement speeds up.
Post Production
I prefer a few programs to create my star trails one of them being StarStaX. It is a free program that is easy to use and seamlessly creates a Star Trails photo. This application takes all the photos and blends them together providing multiple options to choose from and a variety of methods including Gap-Filling and Comet Trails which are my favourites. StarStaX also allows the use of Dark Frames - which helps to eliminate hot pixels - provided I remembered to take one after shooting all of exposures. Another feature I like is the function to Cumulative Blend. This allows each photo to be processed and then save the composite image as a part of a sequence. Later when all these sequential photos are imported into a program like After Effects or Premiere Pro it is possible to create a beautiful Star Trails video. The video you see here is an example of this process.
Other programs like Sequator for Windows and Photoshop can also be used. I find that Photoshop creates the highest quality Star Trails however, this is by far the hardest and most time-consuming option. I would recommend sticking with StarStaX.
In conclusion, Star trails photography is fascinating, and it should be attempted by everyone at some point. Unlike Milky Way photography, Star Trails can be don’t at any time of the year. It is a kind of photography that requires some patience given that the shooting process takes a few hours but the results are worth it.
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