To the amateur astronomers out there — I know, I know. A 60mm telescope isn’t exactly an impressive rig. I would never have purchased such a borderline toy telescope, but that wouldn’t prevent me from taking one if I just stumbled across it. And a few weeks before the eclipse, this exact thing happened. On trash day in the college town I live in with my academic partner, this Celestron called to me while I was walking the dog and, low power or not, it deserved better than the garbage dump.
Plus, you know, it was $FREE.99.
I had used it once to observe the Moon. It did … ok, but everything was in functional order. I figured I could clean it up and hock it on Craigslist or Facebook for some beer money. As we rushed out the door, it was the only telescope ready to go, and I reasoned that if we built a homebrew filter, it had the best chance of being the right size.
As it ended up, it was absolutely perfect.
My dad is a sort of amateur engineer, a retired power plant safety guy who seemingly knows everything about home and car repair. We talked about using welding glass, but NASA’s recommendation was at least #14 welder’s glass, and he only had #9 or below, and only in two-inch-wide variations.
We headed to Troyer Enterprises in North Platte to see if they had any. Eclipse observers had picked them dry of anything but 8’s. We left, brewing up ideas. Then I hit on an online thread on Stack Exchange that suggested that you could stack welder’s glass. The math presented was a bit complicated, but basically boiled down to protection number + protection number – 1. Two 8’s would add to 16. Subtract 1, and you…