Poll most knowledgeable amateur astronomers about the best beginner’s telescope, and a 6-inch or 8-inch Dobsonian reflector usually appears at or near the top of the list. The reasons are not hard to understand. This size of mirror gathers enough light to pull in hundreds of objects. The Dobsonian base – a simple up-down-left-right type of rocker box – is easy to understand, and the scope is not so large that the budding astronomer will lose the motivation to bring it outside, night after night.
The Orion SkyQuest XT6 Dobsonian is so simple, a physical description is hardly necessary. It consists of two mirrors, a tube, and a rocker box. Set it on a flat surface, and you’re ready to go. There are no wires, batteries, or computers to boot up. Using a Dobsonian reflector is observing at its purest.
When I was growing up in the 1970s and 1980s, a 6-inch reflector was considered the ideal beginner’s telescope. These days, expectations have grown, and now you will often see an 8-inch recommended instead. If you are ambitious, go ahead and get the 8-inch, but the 6-inch still has its place. It costs about $100 less, and it’s lighter. Note, however, that all of the weight savings is in the optical tube (13.5 lbs/6 kg for the 6-inch, 20 lbs/9 kg for the 8-inch). The weights and footprints of the bases are the same for both models.
The Orion XT6 is the most common 6-inch Dobsonian on the market. In the past twenty years, there have been many minor variations; none are significant, with one exception. Starting in the mid 2000s, Orion substituted the stock 1.25-inch metal focuser with a plastic one. This plastic focuser is a concern; once damaged, it can be hard to replace. For this reason, I tend to steer people to the larger 8-inch XT8 model, not just because of its larger aperture, but because it has a superior 2-inch metal focuser. Am I overstating this problem? Perhaps. Many XT6 owners go their entire lives without an issue with this focuser. But for me, it is always in the back of my mind when I use an XT6, and I am careful to treat the tube gently while transporting it.
What can you see with a 6-inch reflector? A lot! Start with the moon, and be sure to check out Saturn and Jupiter if they are up. Beyond the moon and planets, hundreds of deep sky objects await you. There is almost no end to the number of clusters, nebulas, and galaxies that can be seen by the patient, motivated observer under dark skies. There’s no astrophotography to speak of; a Dobsonian is a visual telescope.
The success of the XT6 has not gone unnoticed. There are now several competing models on the market, from manufacturers like Apertura, Zhumell, GSO, Explore Scientific, Sky-Watcher, and others. Some come from the same factory as the Orion XT6 and are virtually identical, though often with different accessories, while others are “ground up” redesigns. Some are even supplying metal focusers, albeit at a higher cost. All are recommended; buy the one that has the features you need, at the price you are willing to pay.
The Orion XT6 remains an outstanding choice for beginning astronomers, twenty years after its launch. I’ve said this many times before: A mid-sized Dobsonian reflector is cheap, simple, and will teach you a lot. It will keep you busy for a long time, possibly forever.