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Paul Ingraham, the crescent moon, and the crescent Venus, ca. 1985. — Bob Ingraham Photo

Dobsonian telescopes were popularized by the amateur astronomer John Dobson in the 1960s. Dobsonians are basically Newtonian telescopes, invented by the British scientist Sir Isaac Newton in 1668, and utilizing a concave primary mirror and a flat diagonal secondary mirror. Dobsonians — often called “light buckets” — are optimized to reveal faint deep-sky objects such as galaxies and nebulae. They are inexpensive, easy to use, relatively easy to transport (depending on the size of the primary mirror!), and popular in the amateur telescope making community, where the design was pioneered and continues to evolve.

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