Dobson Astro-Initiatives
4 HN recommenders · recommended in 5 months, 2017–2025
1:28:31 · 1.7M views · Dec 9, 2014
A roughly 90-minute film of John Dobson building a Dobsonian telescope step by step, including hand-grinding the mirror.
Recommended to anyone interested in telescope making as a guide from Dobson himself.
5 comments from Hacker News
The most important thing to look for is the diameter of the aperture. Your resolution is proportional to the diameter of the telescope (absent atmospheric conditions). I would recommend a minimum of 6" in diameter. 8-12" is preferred. With this in mind, the best telescope you can get for the price is a Dobsonian. Dobsonians are extremely mechanically and optically simple. This makes them long, and bulky. It also makes them cheap. It also makes them rather easy to point. They have a lot of mass and inertia, and a large moment of inertia. This makes them easy to move and point slowly and carefully. Dobsonians are ideal beginner telescopes. Easy to point, cheap, good resolution. This is the model I have (8" aperture, $450): [LINK] They're also rather easy to construct, if you are of a DIY mind. Here's a 90 minute youtube video on how to build one, with John Dobson himself: this video
There is also a 90 minutes film »Telescope building with John Dobson« [1], inventor of the Dobsonian telescope [2], going through the entire process of building a 16" telescope from scratch. [1] this video [2] [LINK]
There is a very detailed video documentation [0] about telescope building techniques, featuring insights from John Dobson, the inventor of the Dobsonian telescope mentioned on the page. [0] this video
I like this video from John Dobson about handmade telescopes, where he builds a complete telescope including hand grinding the mirrors. this video
I'm not sure if it will necessarily be cheap, maybe cheaper than an off the shelf mirror of equivalent size. This is what John Dobson (of the Dobsonian) is famous for. However you still need to do stuff like coat the primary mirror once it's polished and you can't easily do that at home. See this video