Looking up at the Cape Palliser lighthouse with the Milky Way above. I shot this with a 14mm lens set with the focus manually set to infinity. The image has a relatively large depth of field due to the short hyperfocal distance that you get with the 14mm lens
Planning is one of the most important things to do when going out to shoot the night sky. You could go out there and photograph without some kind of planning, but it’s always a good idea to know your locations beforehand, and what you plan to shoot. I always have an idea in my head of what I want to shoot before I go out, although I certainly don’t get exactly what I had planned every time. Sometimes I come home with nothing worth looking at, and other times I manage to capture a great image that is totally different to what I planned in the first place.
Another planned pano – I wanted to capture the entire visible Milky Way in this shot and the two Magellanic Clouds. It took over 30 minutes to shoot the 56 images that make up this pano and a lot of work to stitch all those images together!
Camera Settings
With all forms of astrophotography you will need to shoot manually on all your settings. This is because the camera will not be able to correctly evaluate the automatic settings with the available light at night time.  Doing this will also give you consistency across your astro shots. I’ll go through these settings below, as well as the factors to consider for each.
Exposure. There are two main factors which control your exposure in photography. One of them is the time your shutter is open – shutter speed – and the other is aperture . The combination of these two determines how much light hits your sensor for giving you the final image. In astrophotography, you will be dealing with long exposures as you are photographing objects in the dark.
Shutter Speed is the amount of time your camera shutter is open to allow light onto the sensor. In astrophotography we need a long shutter speed to allow enough light onto the sensor. We also have to consider that the longer you leave the shutter open, the more star trails or streaking of stars you are going to get due to the earth’s rotation. This may be a desired effect if you set out to capture star trails, but generally you want to avoid them in your wide field astro photos, so it’s important to know how long you can expose for before you get star trails. This will vary depending on what focal length lens you use. The longer the focal length, the shorter the exposure time will have to be before getting star trails. Thankfully there is a formula for this called th e 600 rule . This rule is simply 600 divided by the true focal length of the lens you are using. And by true focal length, it’s the focal length of the actual lens only if you are using a full frame camera . If you are using a camera that has a smaller sensor, you need to factor the crop factor into the focal length. For example, if you were using the Canon 7d , which has a crop factor of 1.6 with a 10mm lens , then your true focal length would be 10 x 1.6 , which is equivalent to a 16mm field of view on a full frame camera. Now since you’ve grasped the crop factor concept, lets go back to our 600 rule. So on a full framed camera, the maximum shutter speed you could use before seeing star trails when using , say , a 24mm lens is: 600 divided by 24mm = 25 second exposure. If you were using that same lens on a smaller sensor with a crop factor of 1.6, your maximum shutter speed would be: 6 00 divided by (24mm x 1.6) = 15.625 seconds.
Aperture is the diaphragm mechanism of your lens which controls how much light gets through to the sensor in the camera by opening and closing. You can think of it as the same way the pupil of your eye works – the pupil gets wider in the dark allowing more light through your eye, but narrower when there is light, to allow in less light. We define aperture as stops, and the setting you will change to control your aperture on your camera are f-numbers . In astrophotography, we need as much light to pass through the lens and hit the sensor as possible, so we generally shoot wide open, or at your lens maximum aperture. The lenses I use have a maximum aperture of f/2.8, so this is the aperture setting I use a majority of the time for my wide field astrophotography. If I’m shooting something a brighter, like the moon, and I want to see some detail on the surface of it, then I will usually stop down (make the aperture smaller to let less light in) to around f/9
ISO. Modern DSLR cameras are capable of high ISO s, which is great for astrophotography, as by setting a high ISO your camera is able to pick up more detail than the naked eye can see. An ISO in digital photography measures the sensitivity of your image sensor in your camera. The higher the ISO value, the more sensitive or amplified your image sensor is to light. The only downfall is that the higher the ISO, the more noise you get in your image , but this can be rectified to a certain degree with noise reduction in post. And since we are shooting in darkness, we want to be able to shoot at the highest ISO possible without getting too much noise in the image that we will not be able to control with noise reduction. For me on my Canon 5D MkIII , this is between and ISO of 3200 and 6400. For other cameras this may vary, and you mightn’t be able to push your ISO so far, but it’s worth experimenting to see just how far you can push your ISO without too much image degradation.
White Balance  is the process of removing unwanted colour casts and instead  giving you an image with neutral whites. This value will vary under different lighting sources, so that’s why it is important to manually set this value for astrophotography. Some people set the white balance to one of the presets on their camera ,like daylight for example, and then deal with neutralizing their white balance in post production. This is totally ok when shooting raw. If you are shooting jpegs (not recommended for night time photography) then you need to get your white balance as correct as possible – this will need to be set manually. For astrophotography, this can vary between 3200k to 4800k depending on the lighting conditions. You could also use the tungsten white balance preset as this is approximately 3200k.
What Settings Do I Use? There are numerous factors for this and it will mostly depend on the type of camera and lens you use, and how dark your shooting environment is. For example, I shoot with a Canon 5d MkIII and a 14mm f/2.8 lens, so in a dark sky environment, my typical settings are a 30 second exposure, aperture f/2.8 and ISO 3200. These setting may vary for you when taking into account the environment and the equipment you are using, and are something you will need to experiment with until you get a result you’re happy with.
Photographing people against a starry sky can certainly look impressive. The trick is you need your subjects to stand still for at least as long as your exposure. In this case, I was the person who had to sit still for 30 seconds.
Composition
With wide field astrophotography, no matter how spectacular the night sky is, marrying the landscape with the sky in an aesthetic way is a must if you want to end up with an image that stands out from others. With the correct settings, anyone can point a camera and take an ok picture of the night sky. But the difference between an ok picture and a great picture is usually composition.
Composition is something that can come naturally to people who have an artistic eye, but others struggle to grasp it and cannot see a good composition even when it’s right in front of them. Thankfully there are simple rules to help those who can’t easily see a good composition, and if you are aware of and plan your shots around these rules, then composition may start to come more naturally to you.
Below are just a few of these rules:
The Rule of Thirds. It’s a rule based on breaking an image down into thirds, both vertically and horizontally. The idea is that you place your point of interest on one of the intersections of these thirds to give you a pleasing composition.
Points of Interest. An image without a point of interest will not hold the viewer’s attention for long. It could be something as simple as a tree in the foreground silhouetted by the night sky, or the Milky Way hanging low over the horizon of mountainous landscape.
Make sure your horizon is straight. Unless you are deliberately going for a dutch tilt , it’s really important in any landscape photography to make sure your horizon is straight. This same rule applies to wide field astrophotography if there is a horizon in your shot.
Good composition is the key to any kind of photography. This image was shortlisted for the 2012 Astronomy Photographer of the Year due to its pleasing juxtaposition between the foreground tree and The Milky Way.
Digital Processing
This topic can certainly be a tutorial on its own, so I’m not going to get into specifics here. Perhaps I’ll do a tutorial on processing another time, but I will talk briefly on the subject and share my personal preferences on processing.
Before we had digital cameras, photos were processed in the dark room with chemicals and photographic paper. Now in the digital age, that processing is done on the computer. It’s certainly not exactly the same kind of processing, but you can use old darkroom processing techniques like dodging and burning in the computer. Software like Photoshop , Lightroom and Aperture can also give you a lot more freedom with your processing techniques, especially when you are using the RAW image format .
This is great for astrophotography ,as it can give you a lot of control over your image. But it can also be a double edged sword, and personally I find some of the processing of wide field astro images out there a little over the top. I like to keep my astro images as natural as possible, and process them according to my interpretation of how I saw the scene on the night. This includes making sure mywhite balance is relatively neutral, and not pushing the clarity too much, leaving halos on every edge, or crushing the blacks so much that there is no image information left in them. To the untrained eye, you might never see that there is an issue, but it is important when producing good quality astro photos that you keep your processing in check.
All of this boils down to good in camera techniques, so really all there should be to do when you come to process your astro photos is to get your white balance in order, correct the exposure if need be, set your white point, add some contrast and control your noise with noise reduction . Much beyond this, and you may find your image begins to fall apart with processing artifacts.
In the end, processing is very personal and the style of your processed image will vary from one person to another. I’m just giving you my personal view, and some of the things you should look out for.
Before and after processing. The image above is the raw image straight out of camera with no processing at all.
The image below has been processed in Lightroom. I try to my processing as natural as possible without going too over the top.
And as a final word, we can’t get amazing night sky images when it is affected by light pollution so I thought one of the best ways to educate people about light pollution would be to show them the difference between a light polluted city sky and a dark sky with little or no light pollution. I used time-lapse photography to demonstrate this, and spent many hours in different lighting conditions capturing the footage. Enjoy the video, and feel free to spread the word!
To see more of my work, you can follow me on 500px or visit my website, TheArtofNight.com
Got any questions for me about astrophotography or my work? Leave a comment below!