If it is good enough for a refractor, it’s definitely good enough for my project. Achromatic doublet design is what people use in refractors. I wanted a high magnification and went for the longest focal length I could find, which was 750mm. Observing the Sun doesn’t require a large aperture, 50mm is more than enough. I chose a Ø52mm f=750mm achromatic double. The distance the light travels before entering an eyepiece is the focal length and it determines the size of the telescope. The idea of a sunspotter is that the light goes through the lens, travels inside the telescope, bouncing from 3 mirrors, enters an eyepiece and the image gets projected on one of its sides. How do you fix the eyepiece in the exact place where it needs to be? How do you keep the lens in place and perfectly aligned?īuilding the telescope was a lot of fun, I’ve learned to use a jigsaw, X-Carve and a 3D printer. The plan is to use it to complete the Astroleague Sunspotter Observing Program, but unfortunately I completed it at the minimum of a Sun cycle, and won’t see any sunspots until next year.
Sun spotter plans full#
Sunspotter is full of little details that make it interesting. The design is inspired by a commerically available telescope, but I’ve done all the designing myself, just for the fun of it. It's compact, light, takes only a few seconds to point at the Sun, and sketching sunspots is as easy as circling the spots on a piece of paper. The Sun gets projected onto a piece of paper after bouncing from 3 mirrors inside the frame. Made this telescope for observing sunspots.