Star tracking is a term that can make newcomers to astrophotography feel a bit star-struck – no pun intended. But once you understand it and begin to practice it, star tracking is not just a technical skill, but a gateway to the extraordinary beauty of the cosmos.
At its core, star tracking in astrophotography involves capturing the stunning spectacle of stars in the night sky as they appear to move across the heavens due to the Earth’s rotation.
In this post, we aim to demystify the art of star tracking and provide practical steps to guide you on your journey to mastering this skill. From understanding the basics to overcoming common challenges and refining your skills, we’ve got you covered.
Understanding the Basics of Star Tracking
If you’re a newbie to astrophotography, you may be wondering about the buzz around star tracking. Well, it’s not as complicated as it sounds. In fact, it’s your ticket to capturing those fantastic, detailed images of the night sky that you’ve been dreaming of.
The What and Why of Star Tracking
So, what exactly is star tracking? Imagine you’re looking up at the night sky. As hours pass, you’ll notice the stars seem to move across the sky. That’s not the stars moving – that’s us! The Earth is rotating, making it look like the stars are on the move.
Now, suppose you want to photograph these stars. Because of this apparent motion, long exposure shots without adjustment will show stars as streaky lines, not the precise points of light we love. Here’s where star tracking comes to the rescue. It’s a technique where your camera moves in sync with the stars, matching their speed and direction. The result? Stunningly clear and detailed images of celestial bodies without any blurry trails.
But why is it so crucial for astrophotography? Well, first off, it allows for long exposures. Some celestial bodies are too faint to see with the naked eye, but with enough exposure time, your camera can pick them up. Without star tracking, these faint bodies might not even appear in your shots. Secondly, star tracking keeps the stars appearing as sharp points of light, letting you capture all the intricate details of the night sky.
Star Tracking vs. Guiding
As you delve deeper into astrophotography, you might come across another term – guiding. Although it sounds similar to star tracking, guiding plays a different role. While star tracking syncs your camera’s motion with the stars, guiding is like its perfectionist partner.
Here’s how it works. A separate guide camera focuses on a single star and monitors it like a hawk. If it notices any slight deviation in the star’s position due to imperfect tracking, it nudges the mount to correct its course in real-time. It’s like having a co-pilot who makes sure you stay exactly on track. So, while you can do star tracking without guiding, using both can lead to even more precise and high-quality images.
Check out our in-depth guide to autoguiding here.
Ready to dive into the world of star tracking? In the next section, we’ll chat about what equipment you need and how to pick the perfect spot.
Getting Started with Star Tracking
Embarking on your star tracking journey is an exciting step in astrophotography. But before you jump in, you’ll need to get equipped with some essential gear and find a suitable location for stargazing.
Essential Equipment for Star Tracking
Before you can start tracking stars, you’ll need a few crucial pieces of equipment:
Camera: Any DSLR or mirrorless camera will do the trick, but those with higher sensitivity to light (indicated by ISO) can capture faint celestial objects better.
Wide-Angle Lens (depending on your target): A wide-angle lens (14mm – 20mm) can help capture a large area of the sky, perfect for capturing the grandeur of the Milky Way or an entire constellation. See our post on wide-field astrophotography here.
Star Tracker Mount: This device holds your camera and moves it slowly to match the apparent motion of the stars. There are various models available, each with different features and price points, so you’ll need to choose one that suits your needs and budget. Check out our reviews of the Fornax LighTrack II and the Sky-Watcher Star Adventurer 2i.
Tripod: You’ll need a sturdy tripod to hold your star tracker mount and camera. Look for one that’s stable and reliable – the last thing you want is your setup toppling over in the middle of a shoot!
Intervalometer: This device can automate your shooting process, letting you take multiple long-exposure shots without having to press the shutter each time.
The Simplicity and Efficiency of Barn Door Trackers
For those just beginning their astrophotography journey, or for enthusiasts looking to enhance their toolkit without breaking the bank, a barn door tracker is a fantastic piece of equipment to consider. Not only is it a cost-effective solution, but it’s also an efficient and straightforward device that can significantly improve your long-exposure sky shots.
What is a Barn Door Tracker?
A barn door tracker, also known as a Scotch mount or Haig mount, is a simple and manually operated device designed to counteract Earth’s rotation. By aligning the tracker with the celestial pole and turning a hand-crank or knob at regular intervals, the attached camera follows the apparent motion of the stars. This ingenious yet straightforward mechanism helps reduce or eliminate star trails in your images, allowing for longer exposure times and thus, clearer and more detailed photographs of the night sky.
Types of Barn Door Trackers
There are several types of barn door trackers, each varying slightly in design and complexity:
- Single Arm: The simplest design, featuring one moving arm hinged to a stationary base. This type of tracker requires careful manual adjustment to track the stars accurately.
- Double Arm: Offers a design improvement over the single arm tracker by reducing tracking errors caused by the tangent error inherent in the single arm design.
- Curved Rod: This design incorporates a curved threaded rod to further reduce tangent error, allowing for even more precise tracking.
DIY Barn Door Trackers
One of the attractions of barn door trackers is that you can build one yourself. With some woodworking tools, a few pieces of hardware, and a bit of patience, you can construct a functioning barn door tracker tailored to your specific needs. There are numerous online tutorials and guides available to help you with this project.
The Charm of Simplicity
While they may lack the precision and automatic functionality of a motorized star tracker, barn door trackers have a simplicity and charm that many astrophotographers appreciate. Using a barn door tracker involves more hands-on involvement, giving you a more intimate connection with the process of capturing the beauty of the night sky.
Whether you’re just starting out in astrophotography or looking to supplement your more advanced equipment, the barn door tracker is an invaluable, cost-effective, and rewarding tool to add to your astrophotography arsenal.
Non-Essential Gear, but Nice to Have!
Wifi control devices such as the ASIair are designed to make star tracking easier and more convenient for astrophotographers. They are essentially mini-computers that connect to your camera, mount, and other devices via USB cables and create a local WiFi network. You can then use your smartphone or tablet to control everything from a single app.
One of the main benefits of using devices such as the ASIair is that they eliminate the need for a laptop in the field. This reduces the weight and power consumption of your setup, as well as the potential issues with cables and software compatibility. You can also enjoy a more comfortable and intuitive user interface on your mobile device, with features such as a touch screen and voice control.
Another benefit of using devices such as the ASIair is that they can perform advanced functions that can improve your star tracking accuracy and image quality. For example, they can use plate-solving to automatically align your mount with the celestial pole and your target object. They can also use autoguiding to correct any errors in your mount’s tracking and keep your stars sharp. They can also capture images in various formats and settings, and preview them in real time.
These devices are compatible with a wide range of cameras and devices from different brands. They can control ZWO cameras and DSLR cameras, as well as focusers, filter wheels, and mounts that support ASCOM or INDI protocols. They can also work with different types of star trackers, from simple barn-door trackers to equatorial mounts with GoTo capabilities.
Devices such as the ASIair are ideal for astrophotographers who want to simplify their star tracking workflow and enhance their results. They offer a portable, versatile, and powerful solution that can handle various astrophotography scenarios and targets. They are also easy to set up and use, with a user-friendly app that guides you through each step of the process.
Selecting a Suitable Location for Star Tracking
Choosing the right location for star tracking is just as crucial as having the right gear. Here are a couple of factors to consider:
Light Pollution: Areas with high light pollution, like cities, can make it challenging to see and photograph the stars. Try to find a dark location, far from city lights. Websites and apps can help you find dark-sky locations near you.
Check out our guide to light pollution filters, or one of our dark sky site guides.
Clear Sky: Cloudy skies can obscure the stars. Check the weather forecast before heading out, and aim for a night with clear skies.
Open Space: An open area with a wide, unobstructed view of the sky is ideal. This way, you can easily reposition your setup if you want to capture different parts of the sky.
In the following section, we’ll dive into the techniques you’ll need to master to get star tracking right.
Star Tracking Techniques
Having your gear and a perfect location is only the start of your star-tracking journey. The next crucial steps involve the setup and alignment of your star tracker mount, and that’s what we’ll delve into in this section.
Setting Up and Balancing Your Mount and Scope
The first thing you’ll want to do at your chosen location is to set up your tripod and mount. Make sure the tripod is on a stable surface, and the legs are spread out enough to prevent tipping over.
Once your tripod is secure, it’s time to mount your star tracker. This is where balance comes into play. A properly balanced mount reduces strain on the motor and allows for smoother tracking.
Here’s how to balance your mount and scope:
- Attach your camera and lens (or telescope) to the mount, but don’t tighten everything down just yet.
- Loosen the axis locks on the mount (both altitude and azimuth), allowing your camera and lens to move freely.
- Carefully adjust the position of your camera and lens until they stay put when you let go. That’s when you know it’s balanced.
- Once balanced, tighten the axis locks to secure everything in place.
Polar Alignment
After setting up and balancing your mount, you need to align it with the celestial pole – a point in the sky that the stars appear to rotate around. In the Northern Hemisphere, this point is close to the star Polaris (the North Star).
Polar alignment may seem tricky at first, but with some practice, it becomes second nature. Here’s a basic guide to get you started:
- Locating Polaris: Start by roughly aiming your polar scope (a small telescope built into your star tracker mount) towards Polaris. You can do this by aligning the mount with the North direction on your compass.
- Using a Polar Alignment App: Next, use a polar alignment app on your smartphone. These apps show you where Polaris should appear in your polar scope at the current time and location.
- Aligning the Mount: Look through your polar scope and adjust the altitude (up and down) and azimuth (left and right) controls on your mount until Polaris sits in the position indicated by the app.
Keep in mind, the better your polar alignment, the more accurate your star tracking will be. This leads to longer exposure times without star trails, resulting in clearer and more detailed images.
After setting up, balancing, and aligning your star tracker mount, you’re ready to start capturing stunning long-exposure images of the night sky.
But remember, like any skill, star tracking takes practice. Don’t be disheartened if your first few attempts aren’t perfect. Keep at it, and with each try, you’ll see improvements.
In the next section, we’ll discuss some common challenges in star tracking and offer advice on how to overcome them.
Troubleshooting Your Star Tracking Endeavors
The Heft of Heavy Equipment
We discussed balancing your mount with a camera and lens, but as you step up your game to heavier gear like telescopes, the balancing act can feel a bit like a tightrope walk. Fear not! The balancing method remains the same—let your equipment find its sweet spot of equilibrium and lock it down. Just remember, it’s heavier gear, so be gentle and patient.
Aligning the Stars, Literally!
Polar alignment might feel like a test of your patience initially. Tiny alignment errors can leave trails on your star pictures, particularly when shooting for longer exposures. However, you can hone this skill with a few tricks:
- Bubble Level to the Rescue: Many star tracker mounts come equipped with bubble levels. Making good use of this can ensure your mount is even-steven, making polar alignment a breeze.
- Fancy Features: Some high-end star tracker mounts and apps offer advanced features to aid in polar alignment, like plate solving or drift alignment. If your gear supports these, it’s worth diving into!
- Practice Makes Perfect: Yes, it’s a cliché, but there’s no better teacher than experience. With every stargazing session, you’ll find polar alignment getting easier.
Light Pollution
Light pollution can be a thorn in the side of astrophotography, dulling out your starry captures. While escaping to a remote dark sky location is the best remedy, it’s not always feasible.
In such cases, a light pollution filter can be your savior. These magical accessories minimize artificial light interference, bringing the twinkling stars into sharper focus.
Weather Woes
Weather can often be a spoilsport, with clouds playing hide and seek with your celestial friends. While we can’t control the weather, here’s what you can do:
- Forewarned is Forearmed: Keep an eye on the weather forecast before you head out, and plan your shoots on clear nights.
- Stay Adaptable: If clouds roll in, take it in stride. Pack up and look forward to the next clear night. Remember, astrophotography is a game of patience!
Up next, we will wrap up our star tracking journey with some additional tips and nuggets of advice.
Final Thoughts and Extra Tips on Star Tracking
Recheck Your Gear
Always double-check your gear before heading out. It’s better to find out you’re missing a cable or battery at home than when you’re out in the field.
Be Patient
The universe won’t hurry for anyone. Star tracking involves long exposures and a lot of waiting, so be patient. Enjoy the solitude and the beauty of the night sky.
Experiment
Don’t be afraid to try different settings, locations, and techniques. The joy of star tracking is as much in the learning and experimenting as it is in the stunning photos you’ll produce.
Join a Community
Consider joining an astrophotography group. You’ll meet like-minded individuals, learn from their experiences, and perhaps make some friends to accompany you on your star-tracking adventures.
And remember, every expert was once a beginner. It’s okay to make mistakes and learn from them. That’s how we grow. So keep your spirits high, your eyes on the stars, and your camera ready. The universe is waiting for you!
FAQ
Can I do star tracking with basic camera equipment?
Yes, you can start star tracking with basic camera equipment like a DSLR or mirrorless camera and a wide-angle lens. However, a star tracker mount is essential for this type of photography.
How important is polar alignment in star tracking?
Polar alignment is crucial in star tracking. Accurate alignment with the celestial pole allows your star tracker mount to follow the apparent motion of the stars accurately, enabling longer exposures without star trails.
How do I deal with light pollution when star tracking?
Choosing a location with low light pollution is best for star tracking. However, if you’re in a location with substantial light pollution, you can use a light pollution filter to help reduce its effect on your images.
Can I do star tracking even if I live in a city?
Yes, but city lights might make it challenging to capture clear images of the stars. You may need to travel to a location with less light pollution for better results.
What’s the best way to learn star tracking?
The best way to learn star tracking is by doing. Get yourself a star tracker mount, read guides like this one, watch tutorials, join astrophotography groups, and start practicing.