By Kevin Berwick
At this point you have 2 options, you can use the supplied paddle or AutoStar
to view in alt-az mode, or you can set up the Autostar to allow full GOTO
operation as well as motorised tracking. Unfortunately, it is impossible to use the telescope manually, you must use the motors to move the telescope. The
big downside of the system is that slewing the telescope is very noisy, the best comparison I can make is that at the top speed, it sounds like a fairly large
radio controlled car. I realise that this may be more of a problem in Europe, where gardens are small, than in the US, where gardens are generally bigger.
However, if you live in an apartment and your neighbours leave their windows open at night, I would factor it in to my purchasing decision. Even when
the telescope is merely tracking, the telescope is too noisy for my liking. It makes a variety of grinding noises whose pitch seems to change a lot over
time, even stopping altogether momentarily sometimes. Initially I thought that it was a problem with my telescope since it sounded like the gears were
literally being chewed but it seems that this is normal. While the noise while tracking won't wake your neighbours, it is slightly alarming and nothing like
the pleasant quiet whine you get from an LX200
for example.
Optics
A star test indicated that the optics were very well collimated, a relief since as I said earlier, if they are knocked out it means a trip back to your dealer.
Anyhow, after the star-test, I took a look at the first quarter Moon. The colour correction is very good, the joy of an almost totally reflective system. Low
power views of star fields, I used the Wild Duck cluster, were superb and indeed, refractor like. Planetary views were a lot better than I thought they
would be. I could easily see Syrtis Major and Solus Lacus, - the 'Eye of Mars', as well as the polar cap on the planet even early on the recent apparition of
Mars. I was very impressed with the optics.
One point that should be mentioned is that you would generally use long focal length eyepieces with this telescope since the focal length is fairly long. On
the plus side, longer focal length eyepieces give good eye relief. In addition, telescopes like the ETX90EC with long focal lengths don't need complex eyepieces to give good images. Plossl eyepieces are perfectly adequate, which should reduce the cost of equipping the telescope with a range of magnifications.
Autostar
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The Autostar hand controller
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The
AutoStar is probably the main reason you would buy this telescope, so a short description of how it works in practice is probably worthwhile here.
Autostar set up is fairly quick, approximately 4 minutes. You point the tube North and after entering the date and time, you simply level the tube, in order
to tell Autostar when the tube is horizontal. After that you align on one or two stars, two is better, and you are ready to go. Initially, I used to be very
careful on the alignment process, for example I used to use a bubble level and compass to determine level and North. However, I now find that this isn't
necessary if you know the position of a couple of bright stars, fixing the telescope on the stars is the critical part of the align procedure. Now I just
'eyeball' level and align the tube with one of my paving slabs before the 2 star align. Once set up, the GOTO system is a real strength of the system. I always got the object I wanted to view in the field of a low power eyepiece after GOTO. In addition, the telescope would track for well over an hour in a low
power eyepiece on average before losing an object.
AutoStar comes with a database of several thousand deep sky objects, more than you could ever view in a lifetime. It has to be said that not all of them
would be spectacular, or even visible, in the ETX90EC. The Autostar system is common across a wide range of Meade telescopes including many with a far
larger aperture. Some degree of discretion is therefore necessary therefore, when planning your night under the stars.
Descriptions are available from the Autostar as to what you are looking at. These are remarkably detailed and come complete with a World Wide Web
style, hypertext system where you can 'drill into' any of the technical terms in the description for further explanation .You can also run 'Guided Tours'
where the system will point to a number of the 'greatest hits' visible that night from your location. A variety of other features are built into this remarkable
system, including a battery monitor, a Help function, power saving utilities and even a torch (which incidentally comes on automatically when you are
prompted for the time during alignment, so you can read your watch - seems that Meade have thought of almost everything!! )
One big strength of the Autostar is that the software is upgradeable via the Meade website at no charge. This means that the GOTO system is continually
evolving, unlike, say, the equivalent Celestron offering. Each new release of the software fixes known bugs and adds features requested by Meade customers. In addition, you can download new guided tours either from Meade or from 3rd parties.
You can also run the system from a variety of Planetarium programs. I tested the system using SkyMap Pro V.8. The telescope successfully established
communication with the PC and after that, you could browse the virtual night sky on your PC and, once you came across something interesting, simply
click GOTO to slew your telescope to the object. Nice!!
You can even look up the orbital elements of spacecraft like the International Space Station on the Internet and track it during it's pass. I haven't done this
myself yet, but it would be nice to try.
I was very impressed with the Autostar. It never crashed on me, except when the batteries ran low and seems at this stage to be a very mature technology, with few bugs left in it.
Summary
Although I have pointed out some deficiencies with this system, you have to remember the incredible value that this telescope represents. You are getting
excellent optics and a very comprehensive and accurate GOTO system for less than the price of a decent bicycle. Sure, you may not be able to hand this
on to your grandchildren, with heavy use I am sure the nylon gears and plastic mount would start to protest, but most people would have upgraded long
before this telescope wears out.
You will get excellent views of the Universe delivered to you painlessly with this telescope, bypassing years of learning the night sky by star hopping. You
can even dabble in astrophotography of the Moon and planets, with a webcam, for example, with this telescope. Of course, it's not perfect, the mechanics
in particular show evidence of economising, but remind yourself again of the price. In conclusion, Meade are to be congratulated on putting this amazing
instrument together, at a price I would never have thought possible.
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Pros
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Cons
Construction quality of mount is very poor
Very noisy slewing
Lightness means that the telescope is prone to shakiness
Poor inaccessible focuser
No provision for user collimation
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US $189.00
AFTER 35 years at Columbia University, where he was chairman of the astronomy department and co-director of the Astrophysics Laboratory, David J. Helfand is on leave to serve as president of Quest University Canada, a tiny liberal arts college in British Columbia that graduated its first class last spring. It is Canada's only private, secular...
