As technology continues to become more accessible for the average consumer, it becomes easier to capture the night sky. This was previously something only the best cameras could do. Most modern full-frame DSLR or mirrorless cameras can capture the stars with ease. However, there are still a few limitations to the process. Even with perfect technique, your images can still be riddled with noise and lacking in detail. Over the last few years, a device called a star tracker has become increasingly popular. This device allows you to take highly detailed images of the night sky like never before. In this guide, I’ll teach you what exactly a star tracker is and why I think it should be at the top of your list to invest in this year.
What is a Star Tracker?
Like all types of photographers, astrophotographers use the exposure triangle to capture photos of the night sky. That is, by extending their shutter speed, opening their aperture, and increasing the ISO to see the night sky. However, due to the Earth’s rotation, shutter speeds are limited. That is, opening the shutter for too long results in stars that appear as streaks. Simply, when you’re shooting from Earth, your camera also follows the Earth’s rotation while the stars remain (relatively) stationary. To compensate for this, you must shorten your shutter speed. This allows in less light and, in turn, results in more noise. I discuss this in more detail when discussing the best wide-angle lenses.
A star tracker is designed to actively combat this problem. Once properly aligned, a star tracker rotates at the same speed as the Earth in the opposite direction. This allows you to extend your shutter speed for minutes at a time to gather more light. Of course, this means a lower ISO, resulting in less noise and more detail.
Why is a Star Tracker Beneficial?
Leaving your shutter speed open for minutes at a time, you can gather far more light. This is typically a better option than tapping into your camera’s ISO for brightness. This produces images that are not only lower in noise but also higher in detail and color with sharper stars. Additionally, most lenses do not perform their best when shot with the aperture wide open. Still, most astrophotographers are willing to make the tradeoff for optical quality instead of having less light when stopping the aperture down. With a star tracker, you don’t have to make any tradeoff – simply extend the shutter speed as long as needed.
Nearly any modern DSLR or mirrorless camera is capable of capturing great images with a star tracker. This means there is no need to purchase the top-of-the-line low-light cameras and lenses. Sure, you could spend thousands of dollars on new camera equipment. There are many reasons to do that for sure! But you will generally gain minimal improvements in low-light performance. A star tracker can range anywhere from $250-$1000 and will give you a vast improvement to your images literally overnight.
Comparing the Milky Way. Above is an untracked image (25s, f2.8, ISO 6400). Below is a tracked image (240s, f4, ISO 800).
Cons of Using a Star Tracker
Before you jump right in and purchase your first star tracker, it’s important to note that there are a few drawbacks. First, because the tracker is rotating to keep your camera on the stars, the foreground of your image (anything touching the Earth) will be blurred. Because of this, you must take an additional image without the tracker to capture the foreground, which you’ll blend together with your sky image later. Many photographers choose to shoot an image during the blue hour, which is the time just before sunrise or after sunset when there is a small amount of ambient light. This time of day yields images that are high in detail and low in noise, perfect for blending with your tracked photo of the stars.
Additionally, the star tracker has a small learning curve when it comes to setup. Most trackers align with the Polaris (the North Star) and require you to manually align the device yourself. There are numerous different methods to do this, including lasers, scopes, and even looking through holes or reticles to perfectly align the tracker. Proper alignment is crucial to the sharpness of your image, as even a slight misalignment will cause the stars in your image to be streaked. Setting up the tracker truly isn’t too difficult, but be aware of the learning curve when getting started.
Best Camera Settings to Use with a Star Tracker
There are many different ways to utilize a star tracker, so always be sure to fine-tune the setup to optimize your images. However, I find a good starting point for my images is at ISO 800, f/4, and a shutter speed of 4 minutes. If properly aligned, you can certainly expose for longer to lower the ISO and remove as much noise as possible from the images. Still, some cameras have diminishing returns past ISO 800, and it is often better to shoot shorter shutter speeds to capture more images. If you want to try longer shutter speeds, you can double the shutter speed and half the ISO to maintain the same exposure value. Keep in mind that the longer the shutter speed, the more pronounced any streaking will be if the tracker is not perfectly aligned.
Best Star Trackers to Buy in 2025
iOptron SkyGuider Pro
The iOptron SkyGuider Pro is one of the best entry-level trackers on the market today, as it’s compact size and polar scope make it easy to transport and easy to set up. An 11-pound payload is capable of supporting almost any wide or mid-range focal length setup, even on some of the larger camera bodies on the market today.
Slik ECH-630 Astro Tracker
If compact is the most important feature to you, the Slik ECH-630 is the ideal tracker. At just 22.4 ounces, this is one of the lightest star trackers on the market today. However, it can only support 4.4lbs, so it’s only an option for lightweight setups.
Sky-Watcher Star Adventurer
The Star Adventurer from Sky-Watcher is one of the most popular trackers on the market, and for good reason. An illuminated polar scope makes alignment easy, and a counterweight that is sold separately can help you stabilize large lenses. If you’re someone who may want to step up to a telephoto lens to shoot deep space targets at some point, this is a great tracker to buy.
Benro Polaris
The Benro Polaris is one of the newest trackers on the market that automates much of the process for you. Once properly aligned, there are numerous in-tracker features like panorama, multi-shot, and custom shutter speed that make the tracking process more automated than ever before. If you don’t mind the extra pricetag, the Benro Polaris is one of the easiest and most effective trackers to use on the market today.
No matter what your experience with photographing the night sky is, one thing is clear: a star tracker will produce images that are practically noise-free and high in detail. If you don’t mind spending a little extra time setting up in the field and post-processing your images, you can produce much better images with the use of a star tracker.
