How to photograph the Milky Way in Cities
If you live in a remote area with dark skies, you are one of the lucky ones; the lucky ones that get to look up on a clear dark night and see a thick band of glowing light stretch across the sky. As a kid I grew up in the countryside of south-eastern Ontario, Canada. On one side I had a corn field and on the other I had a pig pasture. Nights were free from the orange glow of the city and what little light I did see was from the Moon and stars. Being out on those nights and looking up is something I remember fondly. As I got older I was pulled to the energy and activity of city life. In that life I forgot what it was like to have that blanket of stars in the sky at night. Over time I stopped looking upward and more often looked downward into my iPhone. I would read about adventure photographers in remote locations taking the most mind blowing images of the night sky I had ever seen. It made me remember the skies I grew up under. Over time this ignited my passion for being outside at night and exploring. These amazing photographers fuelled my desire to stop looking down and instead look up at the real world that was around me. With this article, I hope to pass on some of what I’ve learned and inspire you to get outside and experience first hand the awesomeness of a crisp, clear, dark night sky near you.
What you will need
A good camera is essential when trying to capture the majesty of the Milky Way. There are many types of cameras that will be capable of taking fantastic images of the night sky. It doesn’t have to be your traditional DLSR camera. There are some great mirror-less options available these days. The Sony ones in particular I’ve read are excellent choices with a wide array of interchangeable lenses. My personal experience has only been with classic DSLRs but as long as your camera shoots in RAW and has manual shooting mode, I think it’s worth giving it a shot. A big factor when considering a camera to use will be its low light capabilities. For the Milky Way you are going to want to get as much light into your camera as you can before the rotation of the Earth starts to blur your image. So using a camera that can shoot a decent image at 1600 or 3200 ISO is a wise choice.
When choosing a lens, I would recommend a very wide angle lens; something that will allow you to capture a huge portion of the sky. The main reason is because the Milky Way is massive! It will stretch across the entire sky and to get it in your composition can be challenging. The wider your lens the more you will see — by wide I mean small focal length. As you get more comfortable shooting the Milky Way you can move in closer with a larger focal length to capture the galactic core and so on. To start out look at something in the 14mm — 24mm range.
The lower the lens’ aperture the better, as you will be able to let in more light with a faster lens. A personal recommendation would be the Rokinon 14mm f/2.8 lens. It’s a “budget” lens but it can produce some of the most outstanding images of the night sky. The bang for the buck is unmatched. My only gripe about it would be the vignetting it produces. Keep in mind, the 18–55mm f/3.5–5.6 kit lens that comes with most entry level DSLRs will definitely work for the Milky Way, so don’t feel you need a special lens to get started.
A Good Tripod
When taking long exposures of the night sky — 15–40 seconds — you are going to need a very sturdy platform to put your camera on. When I started taking night photos I used a cheap $50 tripod and my images were not as sharp as they could have been. This was mostly due to gusts of wind that shook my rig ever so slightly. When you start out, just seeing the Milky Way on your camera’s LCD will be a great feeling. As you progress you will most likely yearn for a crisper image. You can mitigate this shake by using a sandbag or something heavy to hang from your tripod, however this usually means hauling something like that around with you. As you move forward in the craft I would suggest getting a heavy duty tripod that has some weight but is still portable.
When shooting the Milky Way your camera is going to be facing upward in a lot of cases. I would suggest getting a tripod that has a head that gives you the versatility to shoot right into the sky as well as along the horizon. I personally use a 3 way pan/tilt head that gives me the degrees of freedom I need to shoot all sorts of compositions. Ball heads can work as well, but they might be harder to do specific types of things like panoramics or in some cases straight up into the sky.
Using a remote to control your camera’s shutter is essential for shooting the Milky Way. You can get away with using your 2 second delay timer but it will limit you. When shooting the Milky Way you will want to use the ‘Bulb’ mode on your camera instead of the programmed shutter speeds. This will give you full control over how the long camera’s shutter stays open. How Bulb mode works is you hold down the shutter button for as long as you want the exposure to be and when you’re done you let go of the button. This is critical for getting the best shot as you will want to let in as much light as you can before the stars start to create blurry trails in your image. Since you will be holding down the shutter button, pushing the one on your camera isn’t convenient or productive. You will end up with a lot of blurry images due to your body’s movement and the pressure applied to the button on your camera’s body. This is where a remote shutter comes to the rescue. You can hold the remote shutter button in your hand completely independent of the body of your camera, therefore introducing no shake at all. The result will be a consistently sharper image. You can get remote shutters on eBay for a very good price. I’d recommend getting a remote with an intervalometer built in. Not much more money and you can do time lapses!
Taking the shot
Once you’re on site, have your camera ready and your remote in your hand, you’re ready to start taking pictures. This is where the fun begins. Taking shots of the Milky Way is unlike anything else I’ve photographed. In a lot of cases you’re in the middle of nowhere and it’s incredibly quiet. The dark expanse is above you and you’re there soaking it all in with your eyes. The joy I find in long exposure photography is it gives you time to think. Most photos are 20–40 seconds long, so you have time to look up and wonder. Some of my best thinking gets done in between these frames. When the shutter snaps back into position you’re presented with an image of the sky you were looking at, but in a whole new way. In the world of a camera, time piles up upon itself; stacking to create this incredibly detailed image. The longer you let the light spill in, the more hidden details get revealed. The human eye doesn’t work this way. It’s taking in light, storing some of it and forgetting the rest. The light doesn’t get to pile up for long. The time we experience is fixed and constant and we can’t change it. It’s like our eyes have a fixed shutter speed that can’t be adjusted to let more light in. With a camera we get to see nature in a completely different perspective; we get to escape the arrow of time for a brief moment. With this new perspective we get clues to what’s out there and perhaps even figure out how it got there in the first place.
This is probably one of the trickier parts to shooting the Milky Way. Given that the Earth is rotating, objects in our night sky appear to move over time. When taking photos of these extraterrestrial objects we need to pay attention to this rotation so our images come out sharp. This works against us of course, because with long exposure and astrophotography we want to be able to collect as much light as we possibly can. So without venturing into the world of star tracking mounts, you will only be able to shoot for a limited time. There are various rules for how long this time is and it depends on your camera and lens. There are formulas out there that will calculate your maximum exposure time given the size of your camera’s sensor (full frame or crop frame) and the focal length of your lens (14mm, 24mm, and so on). The 600 rule is one of the most common formulas but some prefer to use a more conservative 500 rule. I personally choose to skip the nitty gritty details and just use another iPhone app called Dark Skies. The app is simple, you just input the type of camera and the focal length and it spits out the exposure time in seconds. Use this number as a starting point and adjust your settings to give the best final result.
Aperture and ISO
The other settings on our camera are going to be fairly straight forward compared to shutter speed. For aperture you need to set your lens to wide open or the smallest f/ number. For example the 14mm lens I use has a maximum aperture of 2.8, so I’ll set my camera to it. For ISO I typically choose the highest number that will yield a quality image. With the Canon 6D I have that is typically 3200 or 6400 maximum. Beyond that the noise starts to destroy the image. From here play with the balance of shutter speed, aperture and ISO to give you the exposure you’re after.
When shooting at night it can be a challenge to get your camera to auto-focus on anything. Best forget about auto focusing in this circumstance and change to manual focus instead. Once on manual, move the focus ring on your lens to the infinity symbol. From here if your camera has a live view mode you can fine tune your focus. Flip on live view and then digitally zoom into a bright star. Use the focus ring to bring the star into a sharp focus. From here take a few test shots and zoom in to see how the focus appears. Stars should be solid dots with no halo or bokeh.
When you are out, take a lot of photos. Play with landscape images and portrait images. Take shorter exposures, take longer ones. My only rule is to try and collect as much light as I can. I can take up to 10–20 shots of just one composition with small tweaks to position and exposure. This is how you stumbled on making really interesting Milky Way images, or capturing a surprise shooting star. I tend to always anchor a foreground element that people can identify with to provide the sense of scale. It also draws the eye in and lets the Milky Way play a supporting role to the foreground element. The Golden Ratio always plays into my images first and foremost. After that I’ll try the rules of thirds and see how it changes things. Composition is really in the eye of the beholder. When you are first starting out, a good thing to do is get inspired by other great Milky Way photography and try and recreate it in your own way. From that you’ll develop your own sense of where to place things in the frame. Don’t sweat it too much however, the more images you take the better your eye will get, and really, you probably can’t take a bad picture of the Milky Way.
The Captured Image
Don’t be too disillusioned if the images you capture aren’t like what you’re used to seeing on the Internet. In long exposure photography you are going to be collecting all light around you, not just the light you want. To bring the Milky Way to life you need to post process your images using software like Lightroom or PixInsight. An essential part to shooting a fantastic Milky Way image is to shoot in RAW instead of JPG. RAW images will collect so much more information and give you more room to play in post processing. In a lot of ways when you are in the field capturing your shot, you are doing half the battle. The rest happens when you get home and start processing the image on your computer.
Post processing will allow you to bring out the detail you want in your image and hide the detail you don’t want. It will also allow you to correct some of the imperfections like vignetting, chromatic aberration and distortion in your lens’ optics. Lastly it will help you polish your composition by correcting the white balance, crop, rotation and perspective.
Some believe post processing is cheating or somehow ‘faking it’. It is true that post processing can be taken way to far and create more of a fantasy image rather than an image one might deem as reality. Keep in mind that long exposure photography won’t represent what your eye can see, it will reveal what your eye isn’t capable of seeing. So, no matter what, it might be judged harshly as not looking ‘real’. Knowing this, how far you choose to take your post processing depends on you, the photographer. If you want your images to represent what’s naturally there, I would heed the less-is-more approach when it comes to enhancing the colour in your images. When it comes to shaping the light in the image, the more hidden details you’re able to reveal the better photographer I believe you are.