This Affordable DIY Eyepiece Makes Faint Nebulae Visible Through Your Telescope in Real-Time

It is frankly amazing that humans can see anything at all when we look up at the night sky with naked eyes, considering that the light from many of those stars has traveled thousands of light-years to get to our pupils — millions of light-years if you include entire galaxies. But even with a nice optical telescope, there is still a lot you can’t see without enhancement. That is why Jordan Blanchard designed this affordable DIY eyepiece that makes faint nebulae visible through a telescope in real-time.

Optical telescopes already gather more light than your eyes can, because their objective lenses are much larger than your pupils. It is then possible to further enhance the visibility of celestial objects using everyday photography techniques, like long exposure and digital manipulation, when one pairs the telescope with a camera. But to see the enhanced imagery, the user normally needs to process the photo on a computer and that can dimmish the “live” experience of stargazing.

The solution is an electronic eyepiece, which performs those enhancements and immediately presents the improved images through the viewfinder. There are off-the-shelf electronic eyepieces available, such as the Smarteye Pegasus, but they cost upwards of $2,000. Blanchard’s DIY electronic eyepiece should cost less than €200 (about $236 USD) to build and will fit any telescope with a standard 1.25” focuser.

This design has three important components packaged into a compact 3D-printable enclosure. The first is a high-sensitivity Starlight 1080p camera module with analog output. The second is a 0.39” micro OLED viewfinder display with a resolution of 1024×768 and a 15x eyepiece. The third is a USB-C video capture module, so you can record photos and video to your smartphone.

The camera module does all of the enhancement heavy lifting, with an effective exposure time of about 1.2 seconds (1/25th of a second shutter and 30x boost) and high gain. Those settings are adjustable through the built-in interface (buttons and on-screen display). Then the viewfinder display lets you see the output immediately in what is essentially real-time — certainly close enough to real-time for this purpose.

Of course, the output will be noisy, as that is unavoidable with a sensor at high gain and without more sophisticated digital processing. But it will give you the ability to see more of the universe through the telescope you already own.