What's the difference between a star tracker and an equatorial mount?
Star trackers are very similar to equatorial mounts. The most obvious difference is that they are smaller and more portable. There are a couple of key differences between the two worth noting. To start, star trackers only track in one axis (right ascension), whereas equatorial mounts (EQ mounts) track in both axes (right ascension and declination), which makes EQ mounts significantly more accurate when tracking. For wide angle lenses, such accuracy is often unnecessary. As a result, star trackers are more than adequate for a DSLR or Mirrorless camera and a medium focal length lens. Additionally, most star trackers use a counterweight that's much lighter than the actual payload, if they include one at all.
Theoretically, the lack of a sufficient counterweight can lead to balance issues, but this is rarely an issue unless you're using a heavy lens or telescope. In that case, you might be best served by an equatorial mount. To sum it up, star trackers are perfect for a lightweight travel tracking rig. They are best paired with a DSLR or Mirrorless camera and lens for wide field astrophotography. Equatorial mounts are much heavier and less portable, but can carry a much heavier payload such as a telescope and other imaging accessories.
Which star tracker should I buy?
There are a number of different star trackers out there, and the choices can be overwhelming to a beginner! Currently, the Sky-Watcher Star Adventurer 2i Pro and the iOptron SkyGuider Pro are both excellent options for most skill levels and budgets. They are both very similar, with payload capacities of 11 lbs (5.5 for imaging), connect to your phone via WiFi for control with an app, and use electronically-driven motors to track the Earth's rotation.
If both of those are out of your budget, there are less expensive options, such as the purely mechanical Omegon LX2. This particular model has a much lighter payload capacity, so it can only hold a DSLR or Mirrorless camera and a camera lens — the lighter, the better. But it's also the most portable star tracker option as well.
Do star trackers come with a tripod?
No, star trackers usually come with only the mount head itself, and maybe a counterweight system if you're buying the Pro version. The Sky-Watcher Star Adventurer tripod can work with most star trackers if you don't already own one. If you want a rock-solid tripod that can hold a heavy load, the Radian Carbon Fiber tripod is an excellent choice.
Do I need a ball head for my star tracker?
Most star trackers do not come with a ball head, which allow you to easily orient the camera freely to point it at various targets in the sky instead of only where the star tracker is pointing. Many photography tripods come with a ball head that can be used on star trackers, but If you need one separately, the iOptron Ball Head is a great option.