A simple guide to astrophotography for total beginners with only a camera and tripod
Table of Contents
Astrophotography is one of the most challenging but rewarding hobbies, allowing us to capture the beauty of the night sky. With just a camera, a tripod, and a (possibly wide-angle) lens, it is possible to capture stunning images of the stars, the Milky Way, and even nebulae.
In this article, I’ll go over the basics of starting with astrophotography and getting the best results with your equipment.
By reading and applying all that I’ll write here, I promise you’ll be able to take stunning photos of the Milky Way in no time!
Chapter 1: Equipment and Settings
When it comes to astrophotography, the equipment we use is crucial to getting the best results. A camera with manual controls and the ability to shoot in bulb mode is essential, and any modern DSLR or mirrorless camera can do all of that (just be sure to have the manual with you!).
While full-frame cameras are ideal, crop-sensor cameras can also produce great results. A sturdy tripod is also essential to keep the camera steady during long exposures. A wide-angle lens, 50mm or less, is recommended for astrophotography as it will allow you to capture longer exposures when using only a tripod (more on it below). A lens with a focal length of 14mm to 24mm is ideal, and you can find non-zoom ones for very good prices on the second-hand market.
When it comes to settings, to capture the stars, you will need to use a low or medium ISO, a wide aperture, and a long exposure. It’s best to shoot in manual mode and use bulb mode for the longest exposures. This will give you full control over your camera and the ability to adjust your settings as needed.
This will vary in terms of ISO, but usually between 800 and 1600 is a good value as it allows you to gather more light without too much noise.
As for the aperture, go for the wider F/ value you have available (this is the lower value, not the higher!). We’ll talk more in detail about the advantage of avoiding the maximum aperture, but for now, this will do.
In terms of exposure time, use the time you’ll get from applying the 500 rule in the following chapter.
These settings might be available in manual or bulb mode, so it’s worth setting them at home with your camera’s manual.
I know these terms might feel overwhelming, but sitting during the day with a nice cup of tea and the camera’s manual, you’ll find all of these, and you can experiment easily.
It’s also recommended to have a remote shutter release or a cable release to trigger the shutter without touching the camera to avoid any vibration. Once again, you can find these very cheaply on any online store. No need to be officially from your camera manufacturer.
So, to sum it up:
- Use a camera with manual controls and the ability to shoot in bulb mode
- Use a full-frame camera if possible, but crop-sensor cameras can also work
- Use a sturdy tripod
- Use a wide-angle lens, under 50mm and ideal between 14mm to 24mm focal length
- Use a medium ISO, a wide aperture, and a long exposure
- Use a remote shutter release or a cable release to trigger the shutter without touching the camera
Chapter 2: Avoiding Trailing
One of the most important things to remember when photographing the stars is to avoid trailing. Trailing occurs when the stars appear as lines instead of points in your image. This is due to the Earth’s rotation causing the stars to move across the sky during long exposures.
To avoid trailing, you’ll need to calculate the maximum exposure time for your lens. The rule of thumb is to use the “500 rule“, which states that you should divide 500 by the focal length of your lens to get the maximum exposure time in seconds. For example, if you’re using a 20mm lens, your maximum exposure time would be 25 seconds (500/20 = 25).
If you don’t have a full-frame camera, but instead you have a cropped sensor camera (also called APS-C), change 500 to 300, and the rest of the rule remains the same. So taking the example above, for an APS-C camera, you should divide 300 by the focal length of your lens to get the maximum exposure time in seconds. For example, if you’re using a 20mm lens, your maximum exposure time would be 15 seconds (300/20 = 15).
This rule is just a rough estimate but is very easy. It’s good enough to start, and you can always play safe, exposing for a bit less than that.
In a future blog post, I will discuss the best way to minimize trailing: using an equatorial mount or a tracking device that follows the stars during the exposure and keeping the camera pointed at the same spot in the sky. In this post, instead, I want you to be able to get pictures of the sky using only the equipment you probably already have!
So, to sum it up:
- Remember, the Earth rotates, so the sky and the stars move cyclically every night (yep, Earth is not flat!)
- Use the 500 to calculate the maximum exposure time you can achieve with your lens
- Take some test shots and zoom in 100% on the preview to check if stars are trailing and try again
Chapter 3: Focusing
Another important factor to consider when photographing the stars is the focus. Autofocus will not work well with stars, they’re too far and faint, so it’s best to focus manually (and be sure you disable autofocus and lock the focus once you get it). A trick to focusing manually is to find any bright star in the sky and use it to focus on. Once you do that, your camera will be in focus on any other part of the sky.
To make this easier, use Live View of your camera and zoom in digitally on the bright star you chose (this is essential: do not zoom with your lens, it needs to stay at the widest angle possible).
Using the digital zoom of your Live View, you’ll see your bright star more clearly, and you’ll be able to manually focus until you think it’s the tiniest and sharpest possible on the screen (do not sweat too much over this).
In another blog post, we’ll go over the use of a Bahtinov mask, which is a tool that you place on your lens, and it helps to achieve a precise focus on the stars. But for now, once again, we’re focused (!) on how to do astrophotography without any specific equipment.
So, to sum it up:
- Remember to focus manually (disable auto-focus and lock your manual focus once achieved)
- Use a bright star in the sky to focus on
- Use Live View and zoom in digitally to see the focus better: do not zoom in with your lens!
Chapter 4: Camera and Vibration
When it comes to capturing the beauty of the night sky, the stability of your camera is of the utmost importance. Even the slightest movement or vibration can cause star trails or blur in your final image. I can’t stress this enough, even walking around a tripod while taking a shot can ruin it!
First and foremost, it is essential to use a sturdy tripod. A good quality tripod will keep your camera steady and prevent it from moving during long exposures. Ensure your tripod is level and your camera is securely mounted to the tripod head.
It is also important to use a remote shutter release or self-timer to take the picture. Pressing the shutter button with your hand will cause slight vibrations that can blur the image. A remote shutter release allows you to trigger the camera without touching it, minimizing vibrations. This can happen via Bluetooth or a camera control app on newer cameras or via cable release on older ones.
An alternative is the self-timer, a function available on every camera: typically used to take group photos so you can set the camera and run to be part of the shot. You can use the same function to ensure the photo is taken a few seconds after you press the button and take your hands off the camera. That is enough to make it settle down for a sharp shot.
Another technique to minimise vibration if you use a DSLR camera is to use mirror lock-up function if your camera has this feature (most DSLRs have it). This is not needed on mirrorless cameras because…well they don’t have a mirror!
When you press the shutter button, the mirror in the DSLR camera flips up to allow light to reach the sensor. This action can cause vibrations that can blur the image. By using mirror lock-up, you can flip the mirror up before taking the picture, allowing the vibrations to settle before the picture is taken.
So, to sum it up:
- Use a sturdy tripod and make sure it is level.
- Use a remote shutter release or self-timer to take the picture.
- Use mirror lock-up if your camera has this feature.
Chapter 5: Stacking and Post-Processing
Astrophotography is a bit different from traditional photography. It often involves taking multiple images of the same portion of the sky and then stacking them together to create one final image with less noise and more detail. Simplifying the concept, instead of taking a single picture of 5 minutes, where noise would be high, chances to ruin it with vibrations much higher, you can take 10 shots of 30 seconds each and ‘stack’ them.
This is because long exposures are required for capturing the faint light of stars and other celestial objects like nebulae. But crucially, as we explained before, to avoid star trail, your exposure time has a limit for a single shot, typically between 5 and 25 seconds, and a good astrophoto of the Milky Way will start emerging once you have a total of at least 5 minutes of shots, ideally 10 or more. This means multiple exposures at shorter exposure times.
There are many ways to take multiple shots: first, you can do it manually with your remote or cable shutter. In alternative, many modern cameras allow you to set an automatic sequence. So after you focused and set your exposure time, ISO etc., you can ask the camera to take a series of pictures and wait for it to finish!
Once you have taken your series of images, it’s time to align and stack them to create your final image. We’ll go more into the details in future posts, but the process can be explained very simply for now. The software will align and rotate the single shots using the stars (called registration) for you and then do what it needs to stack and ‘sum‘ the images. This process typically will happen on your computer afterwards.
Many software options are available for this process, and future posts will dive deeper into some of the most complex and famous ones. But for now, one of the more straightforward options is DeepSkyStacker. This software is free to use and can be downloaded from http://deepskystacker.free.fr/english/index.html
You can find many guides and videos about this, so I’ll go here only quickly through the basic workflow. To use DeepSkyStacker, first, launch it and select the folder where your images are saved. The software will then load all the images in the folder and show them in a list. You can then select which images you want for the final image by clicking the checkbox next to each image. Once you have selected your images (useful if any of those has a problem), click on “Register checked pictures” button. This will align all the images so that the stars are in the same position in each image.
Next, you will need to select a reference image. This image will be used as a base for the final image, so choose one that looks good! You can select the reference image by clicking the radio button next to the image. Once you have selected the reference image, click on “Stack checked pictures” button. This will create a final image by combining all the selected images.
DeepSkyStacker also has a feature called “stretch” that can be used to enhance the final image. This feature increases the brightness and contrast of the image to make details more visible. Once you have stretched the image, you can save it in the format of your choice. I suggest saving it as TIFF or PNG, as they’re the best lossless formats, so all the details will be preserved.
Finally, you can further post-process your image using Photoshop or GIMP (a free, open-source alternative). You can crop, adjust the colour balance, and make other fine adjustments to your final image. We’ll go deeper into this in another post!
So, to sum it up:
- Astrophotography works by taking multiple photos of the same thing and then stacking them
- You can see the free software DeepSkyStacker to post-process your photos and the stacking
- Play with the software, and you can try different options and settings to see which works better for your images.
- Learn how to use GIMP or Photoshop to further post-process your final image.
Chapter 6: Your First Astrophotography Night Out
Before you head out for your first-night shoot, remember a few essential things.
First, check the weather forecast and plan to shoot on a clear night with little moonlight.
Next, choose a location with minimal light pollution. This can be challenging, but even small towns and suburban areas can have areas with minimal light pollution if you know where to look. Parks, nature preserves, and other rural areas are also great options. Personally, I do a lot of Milky Way photography when on holiday, as it’s when I typically get access to darker skies.
Make sure to dress warmly, as the temperature can drop significantly at night, and the humidity can make it feel even colder. Layer up and bring a warm drink to stay comfortable throughout the night.
Talking of temperature, another essential factor to consider is the condensation on the lens. The lens temperature can drop below the dew point at night, causing condensation. Basically, the lens surface, exposed towards the cold sky, becomes colder than the air around it, and it condenses. To prevent this, it’s enough to wrap around the lens a hand warmer or buy a dedicated USB lens warmer (available for cheap to buy online) to keep the lens just above the dew point. Having a normal USB phone battery pack can be useful with astrophotography!
Another thing to keep in mind is the battery life of your camera. Cold temperatures can cause batteries to drain quickly, so bring spare batteries or power your camera via USB with the same power bank as the lens warmer!
A final suggestion: Do not use your phone or torchlight to see in the darkness. Get a red light (once again easily available online): this will allow you to not lose your night vision and, at the same time, see what you’re doing. Just remember to switch it off while you take the pictures.
So, once you’re all packed and wrapped up in layers and reached a good relatively dark place, set up your camera on a sturdy tripod and point it towards the Zenith (that is directly over your head), as this is where trailing will be less visible and usually light pollution is less visible. That is an excellent way for your first night out, as it will be mainly for tests.
But, if you feel more adventurous, get Stellarium planetarium/star map software, available for free for all mobile and desktop platforms. Using it, you’ll be able to see the Milky Way, point your camera towards that portion of the sky, and try to get your first Milky Way shot! You’ll likely not see it with your naked eyes, but you’ll be surprised how your camera can see it already with just 10/15 seconds of exposure.
Remember to configure your camera’s settings (as we saw in Chapter 1), keep your lens warm, focus manually, and take multiple shots using a delay shutter release or remote release.
Crucially with astrophotography, take your time and have fun. At the start, it can be challenging and require patience, but it will reward you soon. Remember to take breaks and enjoy the beauty of the night sky.
So, to sum it up:
- Check the weather forecast and plan to shoot on a clear night with little moonlight
- Choose a location with minimal light pollution
- Dress warmly and bring a warm drink to stay comfortable throughout the night
- Consider the condensation on the lens and use hand warmers or USB lens warmers to keep the lens above the dew point
- Keep in mind the battery life of your camera and bring spare batteries or power your camera via USB with the same power bank as the lens warmer
- Use a red light to not lose your night vision and to see what you’re doing
- Point your camera towards the Zenith to start with some tests
- Use Stellarium planetarium/star map software to see the Milky Way and point your camera towards that portion of the sky
- Configure your camera’s settings, focus manually, and take multiple shots using a delay shutter release or remote release
Chapter 7: Let’s wrap it up!
Astrophotography is a challenging but rewarding form of photography, but even with basic equipment, some simple knowledge and techniques, you can create stunning images of stars, galaxies, and nebulae.
Remember to plan and be prepared for the challenges of shooting at night. Dress warmly, choose a location with minimal light pollution, get ready and setup everything, and take multiple shots to stack later.
With a bit of practice, you’ll be able to capture breathtaking images of the night sky that you can share with your friends, and I’m sure you’ll be hooked on a fascinating hobby!
So, to sum it ALL up:
- Use a sturdy tripod. A good tripod will keep your camera steady and prevent any unwanted movement.
- Use a remote shutter release or self-timer. This will help you avoid any camera shake caused by pressing the shutter button.
- Use a wide-angle lens. A wide-angle lens will allow you to capture more of the sky in your frame.
- Use manual focus. When shooting at night, it can be difficult to achieve accurate focus using autofocus. Switching to manual focus will give you more control over your focus.
- Use Live View to focus. When focusing on a bright star, it can be difficult doing it with the viewfinder. But using Live View, you can zoom in the star digitally (the lens must stay at wide angle!) and so see the focus better.
- Use mirror lock-up. If your camera has this feature, use it to reduce camera shake caused by the movement of the mirror.
- Use a delay shutter to avoid vibrations. Check your camera manual for instructions on how to set up a delay shutter.
- Use manual exposure mode. When shooting at night, it can be difficult for your camera’s meter to correctly expose your image. Switching to manual mode will give you more control over your exposure.
- Use Image Stacking. Taking multiple shots and then stacking them will help you achieve a final image with less noise and more detail.
- Wrap up warm and bring a warm drink. Staying outside at night is always colder than you think, because of humidity and in particular on clear nights. So make sure you dress in layers and bring a warm drink to keep you comfortable.
- Take care of humidity on lens and cameras depleting with cold
- Check the weather forecast for a clear night without moon. A clear night without moon will give you the best results for astrophotography.
- Find a space without too much street or artificial light. The darker the location, the better your images will be.
- Point the camera at the Zenith where trailing is less visible.
- Or use a starmap app to find the milky way and point your camera in that direction.
And remember in astrophotography practice makes perfect. The more you practice, the better your astrophotography skills will become.
For any questions, or suggestions to add and expand on this post, please do not hesitate to contact me!