How to Photograph the Milky Way
To photograph the Milky Way with a DSLR camera effectively, you need to take long exposure images using a moderately high ISO setting, and the maximum aperture of your lens. This will reveal more of the structure and color of the Milky Way galaxy in a single image.
A good starting point is to take 30-second exposures at ISO 1600, using an f-stop of F/2.8. By combining multiple images together (stacking), you can create images of the Milky Way a even stronger signal (the amount of light collected) and reduced noise.
The Milky Way captured using a Canon EOS 5D Mark II and Rokinon 14mm F/2.8 lens.
The Milky Way is the galaxy that contains our Solar System. From our vantage point on Earth, we see it as a noticeable band of light stretching across the night sky.
From my latitude in the northern hemisphere, the Milky Way core is only observable between the months of April to September. To photograph it in its full glory, I also need to travel to a dark sky location during the New Moon phase. It’s possible to see the Milky Way from a light polluted city, but it is very faint, and difficult to photograph.
In the following post, I’ll describe my experiences photographing the Milky Way with a DSLR camera. I’ll share the camera settings used, and specific astrophotography tips to help you capture your own image of this natural wonder.
How to Photograph the Milky Way
Have you ever tried to photograph the Milky Way with your DSLR camera? It’s no secret that your digital camera can record much more light than our eyes can see. For this reason, amateur photographers can create incredibly detailed portraits of the Milky Way Galaxy using modest equipment.
All you need is a DSLR camera capable of shooting in manual mode, and a entry-level camera lens. The images of the Milky Way above was captured using a Canon EOS Rebel T3i camera, with a Rokinon 14mm F/2.8 Camera lens. It’s an affordable astrophotography lens that allows an impressive amount of light to be collected in a single exposure.
The Milky Way – Canon EOS Rebel T3i with Rokinon 14mm F/2.8 Lens
Before I go any further, I want to properly set your expectations. My first images of the Milky Way did not look like this, largely because I was shooting in heavily light polluted skies. The photo above uses 3 strategies to create an impressive photo of the Milky Way:
- A tracking camera mount (iOptron SkyTracker Pro)
- A “fast” camera lens (Rokinon 14mm F/2.8)
- Long-exposure Images (2-minutes) to collect more signal in a single frame
- Image stacking to improve the signal-to-noise ratio (DeepSkyStacker)
I’ll cover each of these aspects in the post below. A tracking camera mount like the SkyTracker Pro that compensates for Earth’s rotation is not necessary for success, but it will help pull in more light in a single exposure without star trailing. It gives you more flexibility in the camera settings you choose to shoot the Milky Way, as you can now offset higher ISO settings and low f-stops with longer exposures that use a lower ISO, and slower aperture.
The iOptron SkyTracker Pro Camera Mount.
The biggest advantage a tracking camera mount like the SkyTracker has over a stationary tripod is the ability shoot exposures well past 30-seconds. When the mount has been properly polar-aligned, images of 2-minutes or more in length are possible.
Images that have been captured under dark moonless skies will reveal the individual nebulae and star clusters within the Milky Way galaxy. Certain Messier objects, such as M8, M17, and M20 become obvious glowing pink regions of Sagittarius.
The Milky Way doesn’t just mean the Core of our galaxy, it extends beyond Sagittarius towards the constellation Cygnus the swan. This area of the Milky Way is less dense, but contains some of my favorite deep sky objects within it.
The photo below showcases the Milky Way and the Great Rift in the direction of Cygnus. The Summer Triangle also stands out prominently in this image, featuring the stars Vega, Deneb, and Altair.
The Cygnus area of Milky Way and the Great Rift.
The image above was captured during another memorable trip to the Cherry Springs Star Party. Several images were captured using a DSLR camera on a SkyTracker Pro camera mount.
The Great Rift is a dark band that appears to obscure the center of our galaxy when seen from Earth. It is comprised of molecular dust clouds that sit between our Solar System and the Sagittarius arm of the galaxy. It forms a dark lane that divides the bright band of the Milky Way.
The Milky Way is best photographed without the use of a filter, under pristine, dark, moonless skies. However, if you can’t get to a magical location like this, a mild light pollution filter may help. The Optolong L-Pro is a broadband light pollution filter, which means that it aims to collect natural star colors that make a great Milky Way photo. In my experience, it does a great job of reducing the artificial glow of the city, without disrupting the natural color balance of your image.
The Optolong L-Pro filter is suitable for Milky Way photography.
The 2″ model shown above can be threaded into the optical train of a camera and telescope configuration, but not with a DSLR camera and lens.
There is also a version for full frame DSLR cameras (this one is for full-frame Canon DSLR’s) that sits inside of the camera body. A broadband clip-in filter is worth looking into if you plan on capturing Milky Way images in areas with light polluted skies.
Including Foreground Details
Sometimes you will want to capture foreground details in your Milky Way photo, to show the surrounding landscape below the night sky. For a single exposure on a stationary tripod, this is not an issue because the ground is not moving. However, when using a star tracker to capture images without star trailing, the Earth will show movement in as early as 30-seconds, creating a blurry portion of your image.
This creates a challenging scenario for amateur astrophotographers that want to create an image with a stack of tracked shots, and terrestrial details that are not blurred. The solution is to create a composite image that combines a separate shot (or stack) of sharp, foreground landscape details with a tracked set of images of the Milky Way.
To accomplish this, it is very important to blend the images together naturally, avoiding any hard edges between the night sky, and the Earth below. I find that the best way to do this is to use a feathered mask in Photoshop, with the useful refinement options found in the Select and Mask tool. The image below shows what this mask would look like in an image of the Milky Way with trees beneath it.
Blending images together (using masks) to create a Milky Way composite.
Essentially you want to take a clean shot of the foreground, to replace the blurry version in your night sky stack. The more exposures used for your Milky Way sky, the greater the blurring effect will be on the ground (because more time has passed). You may want to limit your integrated exposure time to about 30 minutes or less, to make the process of blending the images together easier.
How to find it
It might sound like a silly question, as our own Solar System is located inside of the Milky Way galaxy. However, certain areas of the Milky Way spiral are concentrated in the night sky at certain times of the year. The galactic core is the most interesting area of the galactic plane, and what most photographers are hoping to capture.
The galactic core is the most concentrated area of stars in the galactic plane, and what most photographers are hoping to capture. Knowing where and when to look will help you to plan your photo session.
I use an app for my Android smartphone called Stellarium, which will tell you exactly where everything in the night sky will be on any given night. Stellarium is a handy mobile planetarium that is easy to use. Whether you are planning a Milky Way shot or a deep-sky imaging project, this app can save you time and frustration.
I regularly use Stellarium on my PC to plan an imaging session, but having the app on my phone at all times is a real life-saver. Once you know where it is, it’s important to remember some specific camera settings to set yourself up for success.
The Milky Way captured using 30-second exposures on a star tracker mount
4 Things to remember when photographing the Milky Way
- Choose an ISO setting based on your shooting environment. The ISO will need to be much higher than you would normally use during a daytime photo. For moderate light pollution use 1600 to 3200. Pay attention to the histogram, and expose to the right. It’s a balancing act between noise and the amount of light collected. However, with enough image frames, even a noisy image can be smoothed out after stacking.
- Use your camera’s widest aperture, or close to it. Generally, you’ll want to let in as much light as possible, in the shortest amount of time. Fast camera lenses of f/2.8 or below may need to be stopped down a bit for better star quality.
- Set your camera’s drive mode to a 2, or 10-second delay. Better yet, use a remote shutter release cable. Even the slightest movement created by pressing the shutter button can be enough to shake the stars up in your image. Also, make sure your tripod head is locked securely. A sliding tripod head in any direction will show itself immediately in the form of elongated stars.
- Shoot 30-second exposures. This will maximize the light collected in each individual frame. Yes, the stars may begin to trail (depending on your focal length), but this will only be evident when zoomed into 100%.
The Milky Way using the Rokinon 14mm F/2.8 Lens
The photo above uses 60 x 120-second (2-minute) exposures at ISO 1600 with my Canon EOS Rebel T3i. The lens was at it’s native focal length of 14mm, and the aperture was set to F/3.2 for a sharper image.
Stopping down the f-ratio of your camera lens is a commonly used astrophotography tip used to create images with sharper stars. This technique sacrifices some light-gathering ability for a improved clarity and smaller stars. This is one of the many reasons a star tracker provides more options than a stationary mount. You are able to offest the slower f-ratio with longer subs.
With 2 hours of total integration time, I was able produced a final high-resolution photo of the Milky Way with reduced noise and much more detail. Here are the exact camera settings used for the photo above:
Milky Way Camera Settings
- Exposure: 120 seconds
- ISO: 1600
- F-Stop: F/3.2
- White Balance: Auto
- Number of Frames: 60
If you are not using a tracking mount, similar camera settings will still work – but you may need to increase the overall exposure time to produce similar results. Using a lower f-ratio (such as 2.8 or below) can help produce a brighter image in a shorter period of time.
The white balance settings on your camera are not as important as you may think. The key is to shoot in RAW file format so that you’re able to adjust individual parameters such as white balance during post-processing.
The stacking process in DeepSkyStacker registers each image so that the stars align with each other. This process also reduces noise and improves the signal to noise ratio. Subtracting dark frames from you final image is also a key step towards quality data.
Video Tutorial (Stacking in Photoshop)
You can manually stack your images together using Adobe Photoshop, resulting in a smoother image with less noise. This is especially effective when shooting Milky Way photos using a high ISO sensitivity, as digital noise can really start to show itself.
Milky Way Image Processing Tips
For images of the night sky, the preview you see on your camera’s display is only beginning. The true color and beauty of your photo are yet to be brought forth. When you shoot RAW images using a DSLR camera, you open the door to powerful image processing capabilities. Adobe Camera RAW (ACR) is one of my favorite tools for processing astro images.
Adobe Camera Raw
By capturing your images in RAW format, crucial edits can be made to image during the post processing stage. You never want to shoot astrophotography images in JPEG format, as you are losing detail in the image.
I use Adobe Camera Raw to pre-process my images coming into Photoshop. This software supports many different cameras, and allow you to import the images into various Adobe applications from Photoshop to Elements.
Key areas to address in ACR:
- Adjust white balance – less brown, more blue
- Apply noise reduction filter (modest)
- Increase Saturation
- Reduce chromatic aberration (color-fringing)
- Correct vignetting issues
The above list is a small sampling of the actions applied to the Milky Way images on this page. For a really powerful image, try running third party action sets on your image, such as the Astronomy Tools Action Set.
Some of the most effective actions using the package listed above are “make stars smaller” and “local contrast adjustment”. Below, you’ll find an updated image processing video where I process the data from a stacked image in Photoshop.
Travel to a Dark Sky Location
This means that you should plan your shot around the New Moon phase. Even a half-quarter moon creates enough light in the night sky to ruin your image. Having New Moon and clear skies coincide with each other can be a tall order.
This is one of the reasons Milky Way photography can be so challenging.
Light pollution can completely wash away the beautiful structure of the Milky Way galaxy. For this reason, it is essential that you leave the glow of the city behind, and travel to a dark sky location. One of the darkest locations I have been to, is the Cherry Springs State Park. This Bortle Scale Class 2 location is home to the annual Cherry Spring Star Party in Pennsylvania
A camping trip can offer a fantastic opportunity for night photography, as these areas are usually well away from the city. Use a planetarium software such as Stellarium to preview the position of the Milky Way core from your vantage point.
I hope that you have learned a few pointers to apply on your next night of photography. I encourage you to set aside some time to observe the Milky Way under dark skies and feel the overwhelming connection to our universe.
The Milky Way from Northern Ontario during the Perseid Meteor Shower
Keys to a great Milky Way image:
- Use a wide-angle camera lens to capture a large portion of the Milky Way (17mm or wider is best)
- Use a higher ISO setting than you would normally use during the day to collect more signal
- Use your cameras lowest f-stop to collect as much light as possible in a single exposure
- Shoot in RAW mode to adjust variables such as white-balance in post-processing
- Pay close attention to the histogram and “expose to the right”
- Focus using your DSLR’s live view function on a bright star at 10X magnification
- Set your camera’s drive mode to a 2 or 10-second delay to avoid camera shake
- Use a star tracker that has been properly polar aligned to take longer exposures
- Use a remote shutter release cable to automate an imaging sequence
- Fasten your DSLR camera securely into place on your tripod or star tracker
- Take multiple long-exposure images to stack and improve the signal-to-noise-ratio
- Shoot dark frames of the same temperature and exposure length to subtract during the stacking process