Astrophotography: A guide on how to shoot the stars

10 min readSep 23, 2020

Shot of Jupiter, Saturn and the Milky Way from Kohler-Andre State Park in Sheboygan, WI.

Recently I have started getting into taking pictures of the night sky. The picture on the left is one that I took recently. It’s not the most impressive night sky picture that you’ll find on the internet but it’s the best one I’ve taken and it’s one I am proud of.

But when people see this they always seem to ask the same questions. “How did you take that?” “How do I set my camera up to do that?” “What camera do you have?”

I am going to answer all of those questions in this article. I don’t want this to be a full on guide but more of a document that you can use to get you started. This won’t be the last time I’ll say this but you’ll have to experiment with your camera settings to get the best results for your situation. This is probably going to get quite lengthy because it can get quite technical but once you figure it out, you’ll be good to go and take some amazing pictures!

File Type

Shoot RAW. If you should JPEG your photos won’t turn out well. Trust me. Look at your camera’s guide and change file type for photos to RAW.

Camera

The camera that you have isn’t as important as you may think. In terms of shooting pictures of the stars any DSLR/Mirrorless camera will do the trick. You don’t need any special type of camera, so just use whatever you currently have. I’m sure you’ll be surprised by what it is capable of. Obliviously the person who has a Canon EOS R6 or a Sony A7R Mark IV is going to get a better image but they’re also spending around $3,000 just on the body of the camera.

For reference the picture taking above was using a Canon EOS M50. One of the biggest things that the camera will dictate is how high you can push your ISO, but that will come later on. In terms of the equation on getting a great astro-shot the camera has some effect but little compared to the next topic.

Lens

If you want to take a picture like above, you need to find the widest, fastest lens that you have. If you don’t know what I mean by “fastest” lens, it means find the lens that has the lowest aperture number. The lower your aperture number that you have, the more light your lens will let into the sensor of the camera. This is extremely important because in order to see stars and galaxies, you need to let in as much light as possible.

For reference, I wouldn’t use anything over f/2.8 for the best results. If you only have a kit lens that is f/3.5 or f/4, you should be okay. Still go out an try it but you’ll just more than likely need to up your ISO and exposure time. But if you really want to get a shot that has a ton of definition in it, I would try to find a lens that is around f/1.8 or f/1.4. The only downside to these lens are that they usually come with a hefty price tag.

Focal length does become an important factor in determining your max shutter speed before you begin to see star trails. The longer your focal length the shorter your exposure time you can be. This is something that is known as the 500 rule. What this basically states is that 500/focal length is the max exposure time before you begin to see light trails. This is important to keep in mind because you don’t want to take a 30 second exposure with a 200mm lens. The image isn’t going to be clear and you will see lines of light across your screen (unless this is something you are intentionally doing).

When you’re in the field and are getting ready to take your shot make sure you have your aperture set to as wide as the lens will go and pick your focal length based on what you are trying to frame.

My go to lens right now is a Sigma 17–50mm f/2.8 DC OS HSM, this is a great zoom lens and it relatively fast and inexpensive. You can usually find they for sale on eBay for $250-$275.

Shutter Speed (Exposure Time)

This is an example where my shutter speed was too long. Star trails are beginning to form and it looks like the image is out of focus. This was taken near Rocky Mountain National Park (great place to take astro-pictures).

I’ve already touched on what your shutter speed should be, or the limits that you have based on the lens you are using (I’m going to be a broken record for a second here). Your exposure time shouldn’t be longer than 500/focal length of the lens you’re using. If you follow the 500 rule then you won’t have to deal with star trails.

Just to further explain let’s do some math. If I’m using my Sigma 17–50mm f/2.8 and have it at 17mm, my max exposure time can be 29 seconds (500/17) before I begin to see star trials.

I hate to default to this but your exposure time will also depend on where you are at and what you are trying to take a picture of. For example, if you are in an area that has some light pollution in it you may not be able to get away with a 20 second exposure because the extra light will make the stars not be able to be seen. But if you are in a very dark area you could get away with that 20 second exposure and really make the stars/planets/galaxies pop.

From my experience, I have seem to have found a sweet spot of 10–15 second exposures where the results in my opinion are the best. But this is something you’ll have to experiment with. You might find something different.

ISO

In simple terms the higher your ISO, the lighter your image will be. ISO is going to be one of the most important settings on your camera when taking these kinds of pictures because it will allow for you see more stars and galaxies in the RAW image. Since you’ll be shooting in a very dark environment this will become important to push your ISO to a high level, but this will come at a cost.

When you push your ISO to the higher levels of your camera, you begin to introduce noise into the image. If your images begin to look grainy or slightly out of focus, you should think about lowering your ISO. Every camera will be different with the levels of the ISO they can go to before they get too much grain in the image.

For perspective, on my Canon M50 (which doesn’t handle high ISO well at all) I usually shoot around 800–1000 before the image quality begins to turn bad. If you have a higher end camera, like the cameras that I mentioned above, you might be able to push your ISO to 3200. This is just something that you’ll have to experiment with again but around 1000 should be a good starting point. Your ISO level will also depend on what your exposure time is and if there is any light pollution in the area.

Setting Focus

This is probably going to be the hardest thing that you have to do but don’t be scared or intimidated by this part. There are a few tricks that you can take advantage of to make your life a lot easier.

You may be asking, “how do I set my focus when my screen is essentially black and I can’t see anything?” That’s a fair question. I thought the same things when I was beginning.

First, you have to be in manual. This will not work with your lens or camera is in auto-focus mode. Then if your camera has it, turn on focus-peaking. What this will do is turn anything that is in focus to the color red. I have found this being one of the biggest helps in making sure that my camera is in focus because you get a visual que and confirmation that you are in focus. After that just rotate your focus ring until the brightest object in the sky is outlined in red.

If you don’t have focus-peaking or just don’t want to use it, don’t worry. There are plenty of other things you can do. One trick that I use is finding the brightest thing in the sky and making that my focus point. After you do this, rotate your focus ring until that object is tack sharp. You’ll know what I mean when you are out there doing this. At first the object will look large and sort of fuzzy but as you focus in on it, it should begin to get smaller and turn into a very bright little point. Stop when you see that, that means you are in focus.

It may take a few tries to make sure that you have your focus properly dialed in but that’s okay, don’t get discouraged if you don’t get it right away. It isn’t easy.

Using a Tripod

You have to use a tripod to do this, there isn’t any way around this. The camera must be absolutely still in order to get a high quality image. It doesn’t really matter which kind of tripod you are using but it just needs to hold the camera still. It won’t be possible for you to hold your camera still for that long. Don’t waste your time trying.

Since I’m purely into photography, I really like ball head tripods. They make manipulating the camera into the correct position really easy and they’re extremely versatile. I’ll link the one I have below. To be honest, I had just a $15 tripod from Wal-Mart for quite awhile and it did everything I needed. It was just really cheap and you could tell (obviously).

Finding a Dark Area & Stars

To get the best results you need to find a dark sky area. This is probably harder then you think and depending on the area that you live in, it might require some considerable driving. To help find these or just understand how much light pollution is in your area, refer to this website: www.lightpollutionmap.info

When finding these dark sky places, make sure you’re following all rules and not trespassing on private property. Just be respectful.

For reference, the first image in this article was taken in Sheboygan, WI where there is some considerable light pollution from Sheboygan itself and from the Milwaukee metro area. But as you can see, you can still get some pretty good results, even if your area isn’t a dark sky. Just try it out and you might be surprised how capable your camera is.

In the digital age that we live it, believe it or not, there are apps out there that use AR to tell you where specific stars are! You just need to point your cell phone camera in the sky and have the location setting enabled on your phone. I know, how exciting! So if you are looking to take a picture of a specific star, constellation or galaxy check out one of these apps on your app store of choice.

Editing your Photos

Getting the most out of these photos, they do require a fair amount of editing in whatever software you use to edit photos. My preferred software is Adobe Lightroom, if you’re not using it you should. It’s by far the best in my opinion.

Each photo you take is going to require different steps on how to make the most of it and how to get the colors to pop as much as possible. I did go back and look through a lot of the astro pictures that I’ve taken and I did seem to follow very similar steps for each of them.

My general work flow was: increasing the contrast, decrease the highlights, increase the shadows, increase the whites, decrease the blacks and increase the clarity a little. I usually wait to adjust the exposure at the end depending on the photo.

I usually do end up manipulating the tone curve quite a bit but I’ll leave that for you to explore. This is probably where you’ll be able to bring out most of the stars when editing. It further allows for you to add contracts and also manipulate the shadows, darks, light and highlights. Don’t be intimidated by the tone curve.

Then I will manipulate the HSL tab and add some split-toning based on what colors are showing up the most. In the image at the beginning of the article you can see I really made the blues, purples and oranges stand out. But just do what looks best in your opinion, its your photo and you should edit it to how you like it.

Editing these photos isn’t easy so if you don’t get it perfect or exactly how you want to don’t get discouraged. I often end up editing a photo twice. One of the best pieces of advice I have heard about editing photos is do your initial edit and then forget about it for a few hours. After those few hours come back and make your last adjustments.

Final Comments

I hope you found this helpful. The reason I decided to write this was because I posted some photos to a Wisconsin State Park page and a lot of people commented on how to take pictures like these. I figured since I have take some decent photos I should share my process of doing this. If you do end up going out and taking photos of the stars please feel free to share them with me! Tag me in any pictures or DM me on Instagram (@tysonslade).

Also, if you have any questions please feel free to reach out! I’m more than happy to help out!