Solar Projector

Build your own solar telescope!

This DIY solar telescope projects a clear image of the Sun onto a piece of paper—perfect for safely observing sunspots without the need for filters or an eyepiece. It's an excellent choice for public events, as multiple people can view the Sun simultaneously.

What you'll need
• Standard 50mm finder scope lens (you may need to modify the front element holder to match your lens diameter).
• 1.25" 2x Barlow lens.
• 45.9mm diameter concave mirror, available here: https://www.aliexpress.com/item/1005008294408084.html

• 2020 aluminum extrusion for the frame, assembled with M3 nuts and bolts.
• An M5 bolt and threaded insert for the solar searcher (used as a finder scope).
• 1mm drill bit to clean up the central hole in the finder, if needed.

Once assembled, aim the telescope at the Sun. Adjust the Barlow lens position along the optical axis to bring the image into focus. To change the size of the projected solar image ("magnification"), move the concave mi