From the September 2016 issue

I’ve been thinking about buying a solar telescope, but I already have a 5-inch reflector. Is it possible to convert it into a solar scope? If so, what do I need, and how do I go about setting it up in a safe way?

Taylor Reynolds, Alexandria, Louisiana
By | Published: September 12, 2016 | Last updated on May 18, 2023
Off-axis filters, like the one shown here, are a good way to convert a standard telescope into one for solar observations.
Orion Telescopes & Binoculars

The problem in using a normal solar filter with a reflector is that, because the telescope’s secondary mirror and support are at the front end of the telescope, they interfere with the light and produce a substandard image.

But not to worry! Just get an off-axis solar filter.

This device completely covers the front of your scope but has a 2-inch-diameter (or so) hole that transmits the light. The hole isn’t clear; it’s covered by approved solar film, and that’s what the light travels through before entering the telescope. Be sure to position the filter so the hole doesn’t cross one of the struts supporting the secondary mirror.

You might ask if a 2-inch telescope is enough. Oh, yes. Remember that the object you’re observing is the Sun. There’s plenty of light to go around. You’ll get a nice image that will show sunspots and sunspot groups if any are currently on our daytime star’s surface. Be sure to try different eyepieces to find the best view.

Michael E. Bakich   
Senior Editor