The Ultimate Guide to Milky Way Photography11 June, 2021
Have you ever wondered how photographers immortalize stars or galaxies in their astrophotography? Look no further. We will show you how to capture stunning shots of the Milky Way.
Night sky photography is often associated with cityscapes or starry landscapes, in which the Milky Way dominates the sky.
Photographing the night sky is challenging but rewarding, especially if you are curious about the cosmos. In this article, I will introduce you to the basics of Milky Way and night sky photography.
The Magic of the Milky Way
What makes photographers lose their sleep and venture outside at night with their cameras?
I think that is because we, as humans, view the stars with awe. Most people in the ‘civilized’ world don’t usually have a view of the Milky Way thanks to light pollution.
When a massive power outage struck southern California in the 1990s, Los Angeles residents reportedly called 911 to express alarm about strange clouds hovering overhead. They were looking at the Milky Way for the first time.
If anything, astrophotography has the merit to bring back the magic of the night sky, showing you a sight that you will probably never get to see otherwise.
What Is Astrophotography?
So, what is astrophotography? Loosely speaking, any image of celestial bodies falls under the term ‘astrophotography’.
These images usually include:
- The Moon or the Sun;
- The planets;
- A starry sky; or
- Deep-sky objects such as nebulae, star clusters, and galaxies, including our own, the Milky Way.
While all those targets are pertinent to astrophotography, each one of them requires specific photographic equipment, as well as specific imaging and editing techniques.
We will detail those techniques and gears in dedicated articles; but for now, let’s focus on starry landscapes and Milky Way photography.
Successful Starry Landscape Tips
Before getting technical, let’s look at a list of things you should consider before you venture out under the stars:
- Plan ahead: Check the Moon’s phase and weather reports;
- Location and composition: Know where to find the stars and where the best composition will be;
- Use the proper gear: Using a fast, short focal lens and a tripod is the best place to start;
- Pack appropriately: Nights can be cold, even in summer, so wear layers; it’s better to wear too much than too little. Pack snacks, water, and a frontal lamp (with a red light to save your night vision).
- Pack a binocular: A 7×50 or 8×40 binocular will keep you busy while you’re exploring the starry sky.
Check the Weather
If you want to photograph the Milky Way, you need to find the darkest possible sky you can get.
Checking the weather before you leave home is a good way to avoid surprises. You may also want to check satellite images to assess the risk of clouds rolling in later in the night.
Weather forecasts also provide the phase of the Moon and its rising/setting times.
You can download apps to check the weather, available on both iOS and Android smartphones. A couple of great free ones are:
- Meteoblu (iOS, Android): A free app. It shows radar maps and hourly weather forecasts for up to one week; and
- Clear Outside (iOS, Android): Another free app. This shows sky quality and visible conditions, Moon phase with actual Moon illumination, Sun and Moon rise and set times, plus International Space Station visibility.
Check the Milky Way Visibility
The Milky Way is our own galaxy and we are inside it.
It is visible as a relatively bright band crossing the sky. Its brightness is because most of the visible stars are located in the galactic plane.
The Milky Way is visible all year, but its core rises and sets seasonally. The galactic core is also the most colorful and detailed part of the Milky Way.
In the Northern Hemisphere, the Milky Way’s Core is best visible in spring to late summer, particularly at lower latitudes.
In the Southern Hemisphere, the best period to photograph the core of the Milky Way would be in autumn and winter.
The closer you are to the equator, the higher the Milky Way’s core will be in the sky; making it less affected by light pollution.
Choose the Right Location
Your choice of location will have a direct effect on the type of image you wish to capture.
If you want to capture only the Milky Way, what you have in the foreground is irrelevant. In this case, all you need is a dark location with a view of the galaxy.
On the other hand, if you want to photograph a starry landscape with objects in the foreground, things get a bit more complicated.
First of all, a great sky can’t make the photo: the foreground is as important as the stars above it.
The best way to take a starry landscape, whether you are after a milky way shot, a star trail or simply stars, is to use the same criteria you would use to photograph landscapes in daylight.
Consider the following:
- The landscape must be interesting;
- The foreground must provide a point of interest to hold the viewer’s attention; and
- Pay attention to your landscape composition: use the rule of thirds etc: you still need to balance the amount of sky and land in your nocturnal landscapes.
In addition to those rules, you should ensure the following:
- The landscape is visible and not solid black;
- The sky is sufficiently dark; and
- Your point of view should be towards the target you want to photograph in the sky.
A great location that you can photograph looking at North, for example, is not a good candidate for photographing the Milky Way’s core but could be great for star trails.
Using your phone GPS and sensors, together with augmented reality, these apps show you exactly what can be seen in the night sky from your chosen location. This will help you to pick the right spot.
Find a Very Dark Sky
Finally, before leaving your home, check a light pollution map to see if your chosen location will be dark enough.
Ideally, to photograph the Milky Way’s Core over a landscape, you want to photograph under a sky that has a Bortle scale of 4 (or lower). With brighter skies, light pollution will overcome the faint Milky Way and its colors.
If you want to photograph a wide scene, it’s best to head out around a New Moon or with the Moon low in the sky.
The Moon is so bright at this time that it will naturally light the landscape. The sky will be brighter too, but if the Moon is sufficiently low, small, and not close to the Milky Way, you will be fine.
If you prefer to focus on an element of interest in the landscape, such as a vehicle, house, tree or yourself, you could also do some light painting to light the foreground.
If you cannot make the foreground visible, consider having something, even yourself, in silhouette against the sky.
The Best Camera Settings for Milky Way Photography
Once you are under the stars, it is time to work through an action list of settings. You’ll need to consider the following:
- Use the 500 rule: To calculate how long you can expose before star movement will become noticeable on your images;
- Shoot for image stacking;
- Camera Settings: Shoot in RAW, with daylight white balance, and set the camera in Manual mode and carefully manually focus on the stars;
- Image blending: Consider taking one (or more) photos of the sky and foreground, then choose the best settings for each. You can blend the 2 exposures later in your final image. This will ensure both the sky and foreground are in focus and properly exposed; and
- ISO: Use higher ISO, such as 3200 or more. But remember: the higher the ISO, the more noise will appear in your image. Plus you risk ‘burning’ out the stars to pure white
So let’s take a look at how to set up your shots for the best results.
How to Avoid Star Trails
If you are not interested in creating star trails, you should aim to set your camera to freeze the star movement.
This can be done efficiently by using a tracking device, or, if you are on a tripod, by keeping your shutter speed short.
However, the short shutter speed will be variable and will depend on factors such as the focal length and sensor size.
What Is the 500 Rule in Astrophotography?
The 500 Rule gives you a decent starting point for setting your shutter speed.
This empirical rule states that the longest exposure time (ET) you can use in seconds before stars elongate noticeably. The sum is ET= 500/(CP * FL).
CP is the crop factor for your camera sensor and FL is the focal length in mm of your lens. For example, let’s say you are using a Canon EOS 60D (crop factor of 1.6) with a 50mm lens.
Your longest exposure should be less than 500/(1.6 * 50), i.e. about 6 seconds. If you have a 10mm wide-angle lens, then the longest exposure can be as long as 31 seconds.
Take a test shot and check your stars. You may find they are still too elongated: in this case, use the more conservative 400 rule; ET = 400/(CP * FL).
Another more precise but complicated rule is the NPF Rule, which also takes into account your camera’s resolution.
ISO and Aperture
Once you know how long to expose for spot stars, you need to maximize the amount of light you record in this time.
For this, it is useful to have fast lenses with large maximum aperture or f-stop number, such as f2.
But increasing the ISO will not change your sensor’s sensitivity to light; it will digitally amplify both the signal and the digital noise. Too high an ISO will introduce too much noise and reduce the usable dynamic range of the sensor.
If you track, try using something like ISO 800-1600. If you do not track the movement of the stars, you can test ISO 3200 or more.
How to Focus on the Milky Way
Focusing on stars is tricky, as they are small and faint.
Most of the time, relying on autofocus is a recipe for disaster. The best way to focus on the Milky Way is to switch to manual focus and use your camera’s live view.
Simply magnify a bright star and look at how its size changes during focusing.
The better the focus, the smaller the star will look. Furthermore, faint stars may become visible when your focus is good.
Milky Way Photography Equipment
Choosing the right equipment for astrophotography is essential. But it’s not just camera equipment you need to think about.
In addition to the right camera, lens, and tripod, you’ll need to consider purchasing a star tracker, a light pollution reduction filter, a remote shutter, and an intervalometer.
So let’s take a look at the right equipment to shoot marvelous Milky Way images.
Choose the Right Astrophotography Lens
In general, you’ll want to use a fast lens with a large maximum aperture.
Ideally, you also want your lenses to exhibit low chromatic aberration, coma, vignette and be reasonably sharp when used wide open.
A lens that is usable at f2.8 or f3.5 is a good one to start practicing astrophotography.
The focal length is also important; this not only determines the field of view but it directly affects how long you can expose.
This is because as the stars move across the sky, you must expose for long enough to capture a good amount of light, but not so long that your stars elongate noticeably.