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HM5 Polar Alignment Scope for EQ3-2
by Revier
If you own an equatorial mount then chances are you will be familiar with the necessity of at least a rough polar alignment. Equatorial mounts allow telescopes mounted upon them to follow the motion of the stars across the sky, keeping objects inside the field of view with only a turn of a right ascension or declination nob. This is ... preferable for visual observation but becomes vital for effective imaging (especially when deep sky objects are concerned).
This light weight polar scope fits snugly into an EQ3-2 (CG-4) mount. Before it can be used effectively though, the polar scope itself must be aligned to the mount. This is a simple process that can be done day or night and only takes about 5 minutes to do.
The polar scope is similar to a low powered eyepiece when looked through, with one very important difference, etched onto the glass is a central X marking true north, a small circle in which to position Polaris as well as two other circles for two other bright stars and a diagram representing the orientation of Cassiopeia and the big dipper. When those three stars fit neatly into the etched circles you have polar alignment. It is important to remember though that the diagrams of the constellations are only there as a sign post as to the orientation of the constellations, you will not be able to align the scope so that the etchings fit over the constellations.
The Skywatcher polar scope is indeed easy to use, amongst other examples it holds it's own and is definitely a great choice for £30. Aligning the polar scope takes only minutes and is achieved easily using the three metal thumbscrews on the mount. Setting the polar scope to the correct position within the mount is easy, simply match the numbers on the mount to the numbers printed on the large silver ring around the scope and that's all there is to it.
If you've decided that a polar scope is necessary for you then there really is no need to look further than Skywatchers offering. In essence it does everything that 90% of other polar scopes do for the lowest cost.
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Skywatcher 130/900 EQ-2
by RealHuman
Am I impressed with this little piece of equipment! The only thing important is that you READ THE INSTRUCTIONS carefully, you don't want to damage assembly. This is a very important.
Once assembled the telescope is a breeze to operate and the only thing in your way is the right coordinates and a clear sky. The main downside to ... the telescope is that you cannot look thru the eye piece when doing adjustments but that is not really a big problem.
The moon looks spectacular, other astronomical objects are more fun than the moon tho :-)
Another drawback, if you can call it that is that: you will _want_ to spend a lot on the cool accessories to improve the features and better views, and other cool things like clock drive.
All in all this is a great telescope, and if you don't like what is in the heavens it makes for a cool long distance scope :P .. I would recon it can provide many miles of visibility around you assuming you are high enough and have a clear line of sight.
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Sky-Watcher 'SP-Series' Super Plossl Eyepieces - 20mm
by Revier
The plossl is the most widely distributed and available type of eyepiece available to the modern astronomer , it can be considered the work horse of the eyepiece world. With a myriad of focal lengths and a simple but effective design, its no wonder the humble plossl has come to dominate over such antiquated designs as the Ramsden and ... Huygenian.
Skywatchers 20mm super plossl represents a benchmark in quality within the low cost category of eyepiece. Using the more traditional 4 lens design as Skywatcher have here, enables them to keep a minimum of glass between the observer and the object being observed, until you get into the premium eyepiece category and are willing to pay the correspondingly higher prices the less glass used in an optical system the better.
To go on those lenses, Skywatcher use an excellent multi layered coating to get as much light through, in the most uninterrupted manner possible. The edges of said lenses are also blackened to improve contrast and avoid stray light, one can imagine the importance of contrast when observing the large diffused galaxies the 20mm plossl excels in displaying.
Optically the 20mm performs brilliantly (considering its incredibly low £20 price tag). Of course there are slight coma issues (especially on my f5 Dob), but I've used eyepieces at 3 times the price which have demonstrated worse abberations.
Around the lip of the eypiece is a comfortable fold up rubber cup, to keep out local light pollution, I prefer this design to the twist up plastic shield variety but that will come down to personal taste. A textured rubber safety ring encircles the waist of the eyepiece, which may sound inconsequential but becomes very important when handling the eyepiece with cold deadened fingers, anything which affords the observer extra grip has to be a good thing.
Considering how expensive astronomy can be as a hobby its wonderful to find a bit of kit that performs so well while sporting a ridiculously low price tag, every astronomer should have a handful of Skywatcher's super plossls in their inventory.
To summise, you quite literally won't find a cheaper eyepiece, let alone one that performs so well. Uniting three of the most important aspects of optical quality, practical comfort and affordability shows why Skywatcher are king of the low cost eyepiece.
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