Updates and additional information for readers of Stargazing with a Telescope

 
Chapter 2

More about GO TO telescopes

These instruments have revolutionised the market in the past few years. They were introduced with the promise that the telescope user could now get on with observing objects, rather than just finding them. But many people, especially the beginners for whom they could be so useful, are disillusioned with them. The fact is that it is not easy for any beginner to get the hang of an astronomical telescope straight away – you wouldn't expect to go out and buy a car without passing your driving test.

Various questions in the Telescope Q & A section cover GO TO telescopes, but the main comments can be found here.

The larger GO TO instruments, such as the Meade LX90 and LX200 instruments, have a better reputation than the smaller ones and if you are fortunate enough to get one that works well you will love it.

The Celestron SkyAlign system works very well for beginners, much better than the Meade Autostar system in my view. You don't need to put the telescope into a home position, but you simply locate three bright stars or planets in the sky, without having to know their names. Quicker and more accurate than the Meade system.

Page 21 – hand-held terrestrial telescopes
Earlier editions features the excellent Russian Turist-3 20 x 50 telescope, but this is no longer imported into the UK by Optical Vision. I tried an alternative made by Yukon, but it was a dreadful instrument with very bad field curvature – if the central part of the field of view was in focus, you had to refocus to see something about a third of the way out. I got my money back.

I also tested the Sky-Watcher ST1545, a 15-45x 50 terrestrial telescope which comes on a table tripod. Though it gave adequate images by day, and did allow me to view stars by night (including globular cluster M13) it was not really good enough to be recommended as the full aperture of the instrument could not be used. The images were dim at 20x compared with the Turist-3.

I hope the Turist-3 again becomes widely available as it is an excellent instrument. However, a similar telescope is still listed by the US supplier russianoptics.com as of late 2009, though out of stock.

Page 43 – small reflectors
The excellent Infinity 76 starter scope, of the same design as the Celestron Explorascope, was withdrawn at the time I revised the 2009 edition – not because there was anything wrong with it as a telescope, but because the carrying strap fell foul of the latest toy regulations! However, I am pleased to see that it is now back on sale by the importer, and should be in the shops. The similar Celestron Explorascope referred to in earlier editions is no longer available.

Page 52
Synta (Sky-Watcher) mounts now have GO TO facilities. You can upgrade several of the mounts to their SynScan GO TO system. This requires you to first polar align the mount, but once aligned the system works well.

Page 63 – Collimating a reflector
For a more detailed guide to collimating a telescope, click here.

Page 80
Astro Engineering now make a ‘Polarmate’ polar alignment telescope for LX series mounts with wedges. However, I note from the description that this attaches to the wedge without the telescope in place, unlike the JMI EZAlign which I believe attaches to one of the fork arms. So if you usually keep your telescope on the wedge, you will have to remove it, attach the Polarmate, align it and then put the telescope back without disturbing anything. Not the easiest of things to achieve!

Celestron appear to have withdrawn their own polar alignment scope for their CGE mounts.

Page 97 (2009 edition only)
In the illustration showing the position of the Pole, the labels for 2010 and 2020 have accidentally been transposed.

Pages 162-3
The availability of webcams suitable for astro-imaging has deteriorated in recent years. For a full discussion please click here.

Those are all the updates on the text available at the moment.

Robin Scagell
January 2010

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