Updated: Sep 16
Star trackers are becoming quite popular for landscape astrophotography. That type of device is key for capturing stunning images with the Milky Way in the background. Unfortunately, setting up these special mounts can be challenging and frustrating for beginners.
Setting up a star tracker in the Northern Hemisphere is relatively easy, thanks to a bright star situated very close to the north celestial pole (Polaris). Unfortunately, there is no such bright star in the Southern Hemisphere, indicating the south celestial pole. The stars of the Octans constellation represent the closest equivalent to Polaris, but they are within the human eyesight limit, even in a dark and clear sky.
In addition to that, there are situations where there is no visual access to Polaris or Octans asterism because of a mountain, building, trees, etc. Limiting the compositions and the scenarios that you want to capture just because of that seems entirely unreasonable.
In this article, I’m going to provide some tricks that will make this process easier and faster. This process does not require to have visual access to Polaris or Octans asterism and provides a reasonable alignment accuracy for short focal lengths. Obviously, if you have visual access to the celestial pole asterism, you can improve the accuracy of your alignment.
The described process is also good for setting up a standard equatorial mount for visual observation. If you want to use an equatorial mount for astrophotography with a long focal length, you should consider using an additional step to achieve better accuracy, like SharpCap StellarMate polar alignment. DSO astrophotography with a telescope also requires a guiding system to correct periodic errors of the mount.
You need just a few inexpensive accessories to achieve a painless polar alignment.
Smartphone adapter to a Vixen dovetail or 3/8" screw.
I previously used a rectified timber with a Vixen dovetail section and four silicone stickers to hold the smartphone. It worked quite well, but finally, I decided to design my own adapter. That particular design allows me to use a standard smartphone with a protective case and it also supports QHY PoleMaster. It is compatible with any telescope mount and star tracker with a Vixen dovetail or a 3/8” screw. The model works for the Southern and also the Northern Hemisphere. You order this adapter from the Skylabs NZ website.
This device supports six different setups attending to the type of equatorial mount and the smartphone app / QHY PoleMaster. Check the following diagram to learn what option works best for your equatorial mount.