The Nicest DIY Astrophotography Star Tracker We’ve Ever Seen

Thanks to the tireless march of technological progression, it’s possible for anyone with a few hundred dollars to buy the used photography gear necessary to get started with astrophotography. If you just want to take some pictures of the stars in the night sky, all you need is a DSLR camera with manual shutter settings, a basic lens, and a stable tripod. But you may want a star tracker to take more complex photos. Those aren’t cheap, but redditor Intercipere was able to build their own DIY star tracker with mostly 3D-printed parts.

A star tracker like this one will let your camera move to compensate for the movement of the Earth over time, and can also find specific stars. Astrophotography almost always requires that you leave you camera’s shutter open for a lot longer than you ever would for normal photos. The longer the shutter is open, the more light will reach the camera’s CMOS sensor. That results in a clearer and brighter photo. But it also means that even the tiniest bit of movement will introduce blur. That’s why action photography, such as for sports, requires a very fast shutter speed to capture crisp photos. The movement of the Earth while your shutter is open can be enough to end up with a blurry photo.

This DIY star tracker moves as the Earth does in order to keep stars and other celestial bodies stable in the photo frame. The good news is that this doesn’t require speed. The challenge, however, is that it does require stability and very smooth movement. A little bit of shake will ruin your photo. Intercipere has achieved that with huge gears that surround the camera. Those result in massive gear ratios, which mean the cheap stepper motors that move the camera have to turn dozens of times for every single revolution of the final gears. This keeps movement nice and smooth.

Those stepper motors are controlled by an Arduino board — presumably through a motor driver. The Arduino also has an LCD shield to display information. The gears and other mechanical components are all 3D-printed. Unlike high-end setups, this doesn’t actually have any provision for looking through the viewfinder. That means it has to be positioned and aligned manually, but that’s a minor inconvenience when you consider that the total build cost for this star tracker should be less than $40, which is just a fraction of what you’d pay for a commercial star tracker.