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5.1) What kinds of eyepieces should I use with my telescope?
5.2) What are some popular modifications for Discovery sonotube Dobs?
5.3) Does Discovery ship outside the United States?
5.4) What other mailing lists might I be interested in?
5.1) What kinds of eyepieces should I use with my telescope?
Oh, crud. This is a big question. I'll have to write a lot on this one when I get around to it.
Discovery ships standard eyepieces with its PDHQ telescopes. Sometimes eyepiece packages or kits are thrown in for free or offered at a discount. Many people enjoy memorable views through basic Plossl eyepieces, but many others claim that these eyepieces are of generally poor quality relative to other eyepieces available in today's market.
The answer to this question is probably no different, in principle, than it is for any other telescope: get the best selection of the best eyepieces you can afford.
Discovery is a dealer for several eyepiece lines including Tele Vue. Tele Vue eyepieces are considered in the hobby to be among the very best commercial eyepieces available to the amateur astronomer, and a Discovery matched with TeleVue eyepieces is a very fine optical system. However, the proviso remains: you should have a range of eyepieces which allow you to enjoy objects in a variety of useful magnifications. Having an array of "merely good" eyepieces may be very superior, in practice, to having only one excellent eyepiece. You may disagree.
Here are a couple of personal choices for upgrades on a budget. I would choose a 30mm Celestron Ultima or Orion Ultrascopic eyepiece or a 32mm TeleVue Plossl for low power. Get a 15mm Ultrascopic, Antares "Plossl", or TeleVue Plossl and a 10mm Ultrascopic/Antares. Add a 2x Orion Ultrascopic or TeleVue Barlow, and you'll have good power coverage. This is for an f/6 scope. With an f/5 scope, you might want to hold the top end down to a smaller exit pupil with something like a 25mm. If the budget is less severe, the 24mm or 27mm Tele Vue Panoptics are widely considered to be winners. --Wes Stone There's a lot of advice on this question from other sources, too:
Matthew Buynoski has thoughts and more thoughts on selecting a good selection of eyepieces.
TeleVue's web site has an article on eyepiece selection, involving some of the more technical (but still important!) properties of an eyepiece, such as eye relief.
5.2) What are some popular modifications for Discovery's tube Dobs?
Here are some that popular modifications that I'm aware of:
Flocking. It is said that flocking at least the portion of the tube opposite the focuser aids in contrast. Some claim that flocking a larger portion of the tube helps more.
Baffling. Similar purpose to flocking: keeps scattered light from ruining contrast. Popular spots are the focuser drawtube and the area of the tube behind the primary mirror. Lots of information and discussion can be found on the Cloudy Nights site and the Talking Telescopes Yahoo! Group.
Larger Teflon trunion pads. Out of the box, many people believe that the altitude motion of the scopes is stiffer than is optimal. A popular way to solve this problem is to replace the existing trunion pads with larger Teflon pads. Proponents say that the motion becomes buttery-smooth. Some also contend that the standard pad spacing is too far apart, and that moving the altitude pads closer together gives better results. Others find that everything is OK as is, or that the azimuth motion is the big troublemaker.
Milk jug washers. Popular on DHQ models, supplementing (or replacing?) existing azimuth motion pads in the turntable portion of the Dobsonian base is said to make this motion a lot smoother. Cutting one to several washers out of milk jugs and putting over the center bolt to move between the box base and ground board works for some. Others have replaced the standard pads with virgin Teflon or "magic sliders".
5.3) Does Discovery ship outside the United States?
It has in the past, yes. We recommend you call them directly and ask for details.
5.4) What other astronomy forums might I be interested in?
There are several.
- First, there's a Discovery Telescopes Yahoo Group -- but it gets far less traffic than DDU. You may want to take a look at it. (Archives for members only.)
- Phil Harrington, author of Star Ware, has a Yahoo Group called Talking Telescopes which covers the equipment related to our hobby in vast and overwhelming detail. This is a very high volume list. (Public Archives.)
- Orion's SkyQuest Dob owners congregate on their own Yahoo Group. This is an important resource, not only for those deciding on a scope, but for Discovery DHQ owners since the scopes have much in common. The skyquest-telescopes group also covers Guan Sheng Dobs. (Public Archives.)
- Cloudy Nights has forums as well as reviews and articles. (Generally Public Archives.)
- The BigDob Yahoo Group is for people with "big" Dobs -- whatever that means. :-) (Archives for members only.)
Less directly relevant to Discovery, but still interesting to people like us:
- If you have Usenet access, you should check out sci.astro.amateur, a rather raucous place where lots of amateur astronomers from all over the world hang out.
- For anyone with an interest in TeleVue products, the TeleVue Yahoo Group which is very informative. (Archives for members only.)
- If you have a refractor, you might want to check out the Refractor Yahoo Group. (Archives for members only.)
- Starry Nights is a place where people post their observing reports. A lot of great writing gets posted here. (Public Archives.)
- If you have a passion for planetary observing, you should check out Akkana's The Shallow Sky. (Public Archives.)
- APOD. This is not a mailing list - it's a web site. The Astronomy Picture of the Day is a delightfully educational site delivering a new image and explanatory notes, seven days a week. Superb!
- Sky & Telescope Magazine's AstroAlert News Service, which offers timely information about heavenly events.
- The Astronomical League structures observing by providing observing projects in a way that many people find useful and fun. Taking on projects like these is the way many an amateur astronomer walks the paths of our hobby.
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