Artifacts: Meeting PDF    YouTube Video of Meeting

The meeting took place on October 9, 2025  at 7 PM on Zoom and at the Robinson Nature Center.

Featured Speaker:

Guy Brandenburg

Speaker Bio:

Guy Brandenburg is a retired DC public school math teacher, who made his first telescope in 1991, under the guidance of the late Jerry Schnall, in an ATM class located in DC that still continues today, under Guy’s leadership.

The title of his talk will be “Looking Back at A Century of Innovation in Amateur Telescope Making — and Is It Still Worth It?”

Russell Porter began the first known telescope making class for amateurs in 1920 in an unused basement room of the factory he was working at in Springfield, VT. Using the innovations of people like Isaac Newton, Léon Foucault, Russell Porter, Jean Texereau, John Dobson, and Mel Bartels, many thousands of amateur astronomers all over the world have made telescopes of all sorts with their own hands, from scratch.

While it is true that many others have purchased the materials for such projects but did not complete them, the fact remains that a well-figured Newtonian reflector on a Dobsonian mount, coupled with the free web-page AstroHopper, gives excellent views of bright objects, even from urban street corners, and is also very easy to use.

A Dob is not the best choice for astrophotography, and it’s not so easy to carry one on a plane to a remote dark-sky destination, but making a Dob and purchasing a few eyepieces is a whole lot cheaper than buying apochromats or astrographs, filter wheels, tripods, motorized focusers, astro cameras, specialized software, and highly-accurate computerized tracking mounts. Also, it is hard to beat the exclamations of wonder, amazement, and gratitude one gets from ordinary passers-by on a street corner when they clearly see the Moon, a planet, or a multiple-star system for the first time, with their own eyes, for free, looking through the eyepiece of a home-made telescope that doesn’t wobble.

Guy feels that photographs are fine, but seeing something for one’s self in real time is also great.

Guy will describe and show the basic steps in crafting parabolic mirrors, and will show off some home-made Dobs. He will also explain why you should NOT bother trying to make a refractor or catadioptric yourself, and will discuss whether telescope-making has a future.

Any HAL member who has made a telescope is invited to bring their project (or photos of it) to show off your work as well.

Guy earned a BA at Dartmouth College in 1971 and an MEd (secondary math) at UMCP in 1981. The first astronomy course he ever took was in 9th grade at the same DCPS JHS/MS he ended up retiring from, over 45 years later. He is also currently the president of National Capital Astronomers, founded at the USNO in DC in 1937, and of the private Hopewell Observatory, begun in 1975.

He also  has a well maintained and excellent blog.