Milky Way Photography & Timelapses from light polluted areas

Telangana, India & Malaysia

All of us, especially those who do landscapes, try to avoid shooting a scene with a clear blue sky. As much as we like seeing puffy or stormy clouds to spice up our photographs, we have no control over what nature provides each day. Sometimes we get lucky and capture beautiful sunrises and sunsets with blood red skies, and other times we are stuck with a clear, boring sky. A few days back I found myself in such a situation and decided instead to try my luck with the night sky and the Milky Way.

When you think of photographing the Milky Way, you usually think of doing it from a dark location away from light pollution but given the way modern cities have expanded it isn’t always possible to find a dark location close to any major city especially in a country like India. There is no substitute for a truly dark sky, but I knew it was possible to photograph the Milky Way through light pollution. With this thought I found a couple of locations near my home city of Hyderabad which appeared to have a lower degree of light pollution and made my way there over two nights. Hyderabad itself is a Bortle 8-9 sky as you can see in the light pollution map below but that’s not the end - South India itself is very limited in terms of dark skies. 

Coincidentally it was also almost the new Moon which made the plan irresistible.

Light Pollution Map of Hyderabad, India

Light Pollution Map of South India

I am sure all of us at some point in time have gone out at night to a reasonably remote location and seen an incredibly beautiful night sky with millions of stars shining back at us, or even the beautiful arc of the Milky Way. But to photograph the Milky Way is pretty difficult and the presence of light pollution makes it worse. That said though, it is possible to capture the Milky Way through light pollution by using a technique called Expose To The Right, or ETTR. With this method, you intentionally overexpose your image as much as possible without blowing out the highlights. ETTR allows the camera to capture a better signal to noise ratio – the signal being light, or in this case, the Milky Way.

But when should you start looking for the Milky Way or even better the Core of the Milky Way? When is it visible? Is there a best time of the year to shoot the Milky Way? The Milky Way is visible everyday at night except from heavily light polluted areas of course. However, its Core, the brightest and most spectacular part of the Milky Way, isn’t always visible. So there is a hunting season for the Milky Way.

But why isn’t the core visible? Because for those of us in the Northern Hemisphere, during winter, the Core or the Galactic Center is above the horizon during the day and therefore blocked by the Sun. In the Northern Hemisphere, the Core begins to be visible at the end of January, although for a very short time. Depending on where you are, you will need to wait until February or even March and it stays visible all the way to October when it starts to set and is no longer visible in the months of November, December & January. There are lots of calendars, online resources and YouTube videos available which can help with planning a Milky Way shoot. I personally prefer PhotoPills which provides all the information, and some more, needed to plan.

At the beginning of the Milky Way season, the Core becomes visible in the pre-dawn hours and remains above the horizon during daylight hours. As the months go by, the Core becomes visible for a longer and longer period of time each night, June and July being the months with longest visibility. During this time of the year, the Core will be visible all night. Then from July on, the Core visibility begins to decrease and the best viewing time moves towards dusk and after, until it becomes totally invisible again in winter (November).

Like the Sagittarius constellation, the Galactic Center can only be visible from latitudes between +55º and -90º. If you live in latitudes above +55º, you won't be able to see the Galactic Center and will be able to see only part of the Core of the Milky Way. The best time to see it is before and after summer. Notice that during the summer the astronomical twilight never ends, so you won't have a completely dark sky.

Exif: Canon 7D Mark ii | Samyang (Rokinon) 14mm f/2.8 IF ED UMC | f/2.8 | 14 seconds | ISO 3200 | Manually focused with WB set to Manual at 5500k | 66 Light Frames stacked in Starry Landscape Stacker

Exif: Canon 1Dx Mark ii | Samyang (Rokinon) 14mm f/2.8 IF ED UMC | f/2.8 | 19 seconds | ISO 2500 | Manually focused with WB set to Manual at 5500k | 23 Light Frames stacked in Starry Landscape Stacker

In search of the Perseids

I had actually started out in search of the Perseids.

The Perseid meteor shower, which peaks in mid-August, is probably the best meteor shower of the year with swift & bright meteors frequently leaving long "wakes" of light and color behind them as they streak through the Earth's atmosphere. The Perseids are one of the most plentiful showers with about 50 to 100 meteors seen per hour. They occur with warm summer nighttime weather allowing sky watchers to comfortably view them.

The Perseids are known for their fireballs which are basically larger explosions of light and color that can persist longer than an average meteor streak. This is due to the fact that fireballs originate from larger particles of cometary material & these fireballs are also brighter, with apparent magnitudes greater than -3. These meteors come from leftover comet particles and bits from broken asteroids. When comets come around the Sun, they leave a dusty trail behind them and every year the Earth passes through these debris trails, which allows the bits to collide with our atmosphere and disintegrate to create fiery and colourful streaks in the sky.

The pieces of space debris that interact with our atmosphere to create the Perseids originate from Comet 109P/Swift-Tuttle. Discovered in 1862 by Lewis Swift and Horace Tuttle this is a large comet: its nucleus is 26 kilometers across which is almost twice the size of the object hypothesised to have led to the demise of the dinosaurs. Swift-Tuttle takes 133 years to orbit the Sun once and it was Giovanni Schiaparelli who realised in 1865 that this comet was the source of the Perseids.

Comet Swift-Tuttle last visited the inner solar system in 1992.

Anyway, the two nights I was at the location the Perseids didn’t oblige, although I did see a few streak across the sky, so I decided to focus on the Milky Way. The image of the Milky Way above is a composite of 23 photos, stacked in Starry Landscape Stacker to eliminate noise, taken while waiting for the Perseids near my home city of Hyderabad. Pointing south as the core was setting, this sequence of photos is from the Canon 1Dx Mark ii wearing the Samyang (Rokinon) 14mm f/2.8 IF ED UMC at f2.8, ISO 2500 and exposed for 19 seconds at an altitude of 2,037.73 ft above MSL. The sky here is a Bortle 4 which is basically a brighter rural ambience. Under these skies the zodiacal light is still visible, but does not extend halfway to the zenith at dusk or dawn and there are light pollution domes visible in several directions as you can see here. The clouds are illuminated in the directions of the light sources, dark overhead and surroundings are clearly visible, even at a distance. The Milky Way well above the horizon is still impressive, but lacks detail. The portion of the Milky Way seen here is the section containing the zodiac constellations of Sagittarius Scorpius observed just above the tree. 

For the other photographs I have included here it is more or less the same process but from different locations and using various combinations of lenses with the two cameras. I have included the EXIF information below each photo.

A little bit about Starry Landscape Stacker - a Mac app for making images of the night sky with stars as points and low-noise. It uses "stacking" or "image averaging" to combine a group of images that were captured in rapid succession with identical exposure settings and the camera in a fixed position. The result is an image with stars as points and much less noise than you could achieve with a single exposure.

The basic idea is to take several images (at least 10, more is better) with a high ISO setting (up to ISO 3200) and short exposure time (< 20 sec) each one of which is noisy, and then average these images. The averaging process reduces the noise. The difficulty with this is that the stars are moving relative to the ground so you must separate the sky from the ground and align the stars before averaging both the sky and ground portions of all the images. You can do this with image processing tools like Photoshop, but it is a slow and tedious process. Starry Landscape Stacker will do most of the work for you. Also, Starry Landscape Stacker does not simply average the images, it takes the median of the images after outlier elimination. This produces a much better result than simple averaging and automatically removes airplanes and some other artifacts. Starry Landscape Stacker can also do dark frame subtraction and flat-field compensation to further improve the image accuracy. Although I did take Dark Frames on both nights for both cameras, I didn’t see the need to use them as the Light frames were clean enough. 

You can purchase Starry Landscape Stacker from the Mac App Store or download a free trial.

Exif: Canon 1Dx Mark ii | EF 24mm f/1.4L II USM | f/1.8 | 10 seconds | ISO 3200 | Manually focused with WB set to Manual at 5500k | 75 Light Frames stacked with Starry Landscape Stacker. Note the Sagittal Astigmatism of the lens and the heavy light pollution with some low level clouds.

The devastating impact of light pollution:

More than 80% of the world's population - including me - lives in light-polluted areas, where seeing the Milky Way is usually impossible!

A recent study showed that about a third of the world’s population has never seen the Milky Way with their naked eye. But just a little bit over a hundred years ago everybody could see the Milky Way with their naked eye from the comfort of their garden or roof top. Today almost 70-80% of our population across the globe now lives in an area where they cannot see the Milky Way and there is a funny story about this around the earthquake in Los Angeles in 1994 which caused a power outage. The emergency services that morning were inundated with calls about a weird cloud in the sky. People thought aliens were coming!

That weird cloud turned out to be the Milky Way. They’d never seen it before and didn’t know what was going on and people were terrified.

For Milky Way photography it is best to keep these locations under wraps because an unexploded location, rich with unique photogenic elements, can help to take an award winning image, as simple as that. A second reason is that location scouting can be very time consuming and expensive. I've been scouting half decent locations close to home for some time now with little to no luck and finding pretty unique locations is rather difficult. I feel like the best location is yet to come and my search is still on.

So, what makes a great location in night sky photography?

  1. It is light pollution free which is proving to be rather difficult unless one makes it into Ladakh or the Salt Flats of the Rann of Kutch.

  2. It includes a point of interest - for example a lone tree, rocks, arches, mountains, monuments, ancient buildings, ruins, temples etc. A few years back I created one such light painted photograph at the Vihara Ksitigarbha Bodhisattva in Bintan. Read about it here.

  3. A place with a hidden story - cemeteries, battlefields, ghost towns, craters, deserts etc. These have an almost hypnotic atmosphere that attracts the attention of the photographer and the audience. Unfortunately in India it is quite difficult to get into places of historical significance for night photography but I keep trying and eventually I hope I will succeed. 

  4. Additional natural events like shooting stars which was what I was hoping to get.

‡‡‡‡‡

Milky Way Timelapse

Now onto the Timelapse.

Timelapses of the Milky Way are a timeless way to capture the natural beauty of our galaxy as it moves across the sky. It helps provide a real sense of how large and beautiful the band looks as it crosses the night sky in video format. As we all know, the Milky Way is a barred spiral galaxy, it is a large object but is not as big as the closest galaxy to us (which, incidentally, is on a collision path with the Milky Way): the Andromeda Galaxy. We, as part of the Solar System, are at about half the distance from the center of the Milky Way galaxy to its outer edges. We are located in a smaller spiral arm – the Orion Arm – between two large arms. Read more

But first things first, what exactly is a time-lapse? It is a technique that allows us to take a series of photos and put them together sequentially to create a video. The frames are taken with the same settings over an extended period of time and when put together show movement from the same perspective in a sped-up fashion. Basically speeding up the passage of time - Time Travel!

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. 

There are some additional pieces of gear required

  1. A wide angle lens which will give a nice wide field of view of the Milky Way.

  2. 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.

  3. A sturdy tripod which is self explanatory as you need a stable base and avoid any shake caused by wind or uneven ground.

  4. A Ball Head to get to the angle required.

  5. 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.

Pro Tip: Do not head north for a Milky Way time-lapse, instead, find a spot that is south of any major city. Why? Orientation matters. The Milky Way will pan across the southern half of the sky. Also, avoid light pollution caused by bright cities to the south and east that create light domes. The light domes you see in my photo here are from some small villages which have been inundated by LED lights - the bane of astrophotography. Why?

The LED lights especially those used for street lighting are INTENSELY bright, much more so than the “old-fashioned” sodiums. Looking up is like staring into the sun. If you have the opportunity, step under an orange sodium street light and then under an LED. You’ll be amazed at the difference in light intensity. Some time back, on a similar Milky Way hunt in Malaysia, to gauge the approximate difference in brightness between the two, I had pulled out my camera and taken a light meter reading on the pavement beneath an LED lamp and then under a high-pressure sodium lamp. The LED was brighter by more than one camera “stop” or more than twice as bright.

Another issue with LED ornamental and street lighting has to do with color. Although natural color LED lighting is available, high-efficiency LED lights emit a much bluer light than sodium vapor. Blue-rich light not only increases the amount of glare sensed by the human eye but also the amount of visible light pollution. Other effects of light trespass and glare include sleeping problems and even an increased risk for certain cancers. From an astrophotography perspective this LED glow is almost impossible to eliminate and believe me I have tried all the night filters available including dedicated narrowband Astro filters. Read about them here - Astrophotography Filters.

We humans need the night more than we know.

LEDs are only part of the problem of course. The real issue is the ever-increasing amount of light pollution worldwide and the potential for new LEDs to make it worse. True, we can take advantage of the  ability to adjust and dim current lighting to more suitable levels. LEDs are also highly directional, making it easy to point them just where they’re needed. Finally, new high-efficiency more natural (less blue) LEDs are now available that can help reduce light pollution. There’s no question that LED lighting can be used wisely to make everyone happy – stargazers, drivers, shoppers and walkers. For help and more information, the International Dark-Sky Association (IDA) is a great place to start.

Anyway back to the Timelapse

To create this Timelapse I have used two cameras with a combination of lenses which you can find in my Kit Bag or a detailed listing here. I have not used any Night/ Light Pollution filters. The exif for the different sequences are as follows.

Exif: Canon 1Dx Mark ii | EF 24mm f/1.4L II USM | f/1.8 | 10 seconds | ISO 2000 | Manually focused with WB set to Manual at 5500k.

Exif: Canon 1Dx Mark ii | EF 24mm f/1.4L II USM | f/1.8 | 10 seconds | ISO 3200 | Manually focused with WB set to Manual at 5500k.

Exif: Canon 7D Mark ii | Samyang (Rokinon) 14mm f/2.8 IF ED UMC | f/2.8 | 14 seconds | ISO 3200 | Manually focused with WB set to Manual at 5500k

Exif: Canon 7D Mark ii | Samyang (Rokinon) 14mm f/2.8 IF ED UMC | f/2.8 | 14 seconds | ISO 2000 | Manually focused with WB set to Manual at 5500k

Exif: Canon 1Dx Mark ii | Samyang (Rokinon) 14mm f/2.8 IF ED UMC | f/2.8 | 19 seconds | ISO 2500 | Manually focused with WB set to Manual at 5500k

Exif: Canon 7D Mark ii | EF 16-35mm f/4L IS USM | f/4 @ 16mm | 15 seconds | ISO 3200 | Manually focused with WB set to Manual at 5500k

Please excuse the two times I have bumped into my tripods in the darkness and also excuse the intermittent flashes of light which were the really powerful headlights from nearby passing trucks. It is unbelievable the sheer number of lights these trucks in India have on them and also their throw.

Note: The EF 24mm f/1.4L II USM is a brilliant lens for astrophotography barring the sagittal astigmatism it exhibits in the corners. To understand more about the lens aberrations and how it affects the photos read this article on Lonely Speck.

Milky Way timelapses don’t need as much control as a day to night time-lapse. In day to night time-lapses, one will have to change the exposure so that the photos look consistent. Fortunately the light tends to be the same in Milky Way photography, so you don’t need to be as alert. The one thing that may get in the way is bad weather, though. Bad weather can make any shoot uncomfortable. It can force one to change the settings or even move the equipment resulting in shaky and unevenly exposed pictures.

The following sequence was filmed in 2019 at Sungai Rengit in Malaysia and played back at three different frame rates. Two cameras and two lenses used, no tracking. A vertical film. Notice how the stars seem to glow when the clouds pass over them.

A time-lapse interval determines how often the camera takes pictures. The more photos you take, the smoother the movements in your time-lapse will look. If you are going to be shooting for hours, the interval doesn’t have to be that short. The longer the interval is, the less overwhelmed the camera will be over a long period. Also keep your camera battery and memory in mind when you set an interval. For Milky Way Timelapses it isn’t always necessary to use short intervals. Stars don’t move fast, so the interval can be pretty long. It can be anywhere from 15-35 seconds long. It is basically dictated by the Lens and Camera combination and how much time they allow for stars to be sharp and maximum signal acquisition. Also it is best to shoot in RAW and Manual Mode although it isn’t necessary. It’s just that RAW and Manual modes give the maximum control over all variables. The shutter speed depends on one’s creative preferences. Slow shutter speed is ideal for star-trail timelapses. You’ll get a silky effect that will make the stars look like the ones in this video below I’d taken some time back from my rooftop a Bortle 8-9 sky.

The Milky-Way is stunning! It’s the perfect subject for nighttime time-lapse photography. When you take pictures, pay careful attention to the camera settings and don’t be afraid of high ISO numbers. You can experiment with a slow shutter speed if you want to create a star trail time-lapse. You can also elevate your Milky Way time-lapse photography by using special tools like motorised camera sliders. But most of all, enjoy the time under the stars!

 
 
 
 
Lights of the Night Sky - Sketch - WIldArtWorks
 

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