Monday, September 25, 2017

Solar Eclipse Pics & Celestron Telescope Filter (3D Printed)

The August Solar Eclipse was an amazing event. Luckily for us, we were only a short 3 hours away from Totality.

In addition to watching the eclipse with my family, I wanted to use my telescope to better see the the event. I have a Celestron NexStar 127STL, which is roughly a 5in Maksutov-Cassegrain. I was surprised after looking on Amazon and B&H Photo, in the lack of available slide-on filters for this size of telescope. So I set off to design my own.

The most important part of this “make” is the ability to block out the harsh brightness of the sun, so I grabbed an appropriate sized solar film. I found a 6in x 6in film on Amazon for around $15.

With that selected, I set out on the slide on filter design. It consists of 2 parts.

  • Primary cap to slide over end of telescope and hold the film
  • Secondary ring to hold film against the larger cap 

Pretty simple to create after measuring the telescope and creating the initial design in SketchUp. I also chose to add some clips to the outer cap to keep the inner ring snug against the cap, therefore keeping the film in place.

With the design completed I printed the two parts, and cut the film to fit inside the outer cap. The print came out great, and for perfectly over the 127STL.

Problem is, this was printed in PLA and I was worried that the hour leading up to the eclipse, would be too hot for the PLA to handle. Reprinted both parts in ABS.

With the final print completed, we drove to St Anthony, ID and set up camp. We were part of a sizeable viewing party, And I began taking photos with my camera about an hour before the eclipse actually started, and let people come up and see the sun in all it's filtered glory in the telescope. Sun Spots were easily visible.

The eclipse began, and a hushed silence and twilight darkness was ushered in as Totality approached. Once we hit full totally, I pulled the filter off, and was a amazed at the detail that was visible,especially the colorful corona  around the eclipsed sun. In person it was amazing, but I wasn't able to really capture it with my DSLR or through the telescope with my phone. I decided to stop messing with it, and just enjoy Totality with my family.

After the event, we drove home and I began to sort through the photos. After minimal editing, I had a pretty good “Timelapse” of the eclipse process.

Here is a modified pictures with the key eclipse phases placed next to each other.

Overall the print worked perfectly, and I will hold onto it for future Sun viewing. Also want to invest in a better camera mount for better pictures, and will be sure to post an update once I have something to show.

Not really eclipse related, but I was able to get some pretty good long exposure shots the night before.

Thanks for stopping by!


  1. Did ABS make any difference with respect to PLA?

    1. PLA doesn't have near the heat tolerance. I wouldn't mess with PLA for anything that would be exposed ro direct sunlight. Go with PETG of you don't like ABS.