Meade ETX 90 Observer Computer-controlled Telescope - We Give You the Stars!

Written by Martin Regtien on . Posted in Miscellaneous

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The observable universe is a fascinating place to discover and even though we have been spoiled with everything that NASA has been bringing out over the last few decades, nothing is as exciting as seeing it through your own eyes with the aid of a telescope.

We have spent quite a few hours over many weeks with the Meade ETX 90 Observer telescope which is a compact and very capable computer-driven system.

And this is what we discovered.

I have had a lifelong interest in observing the stars from the time I built my own 100 mm reflector telescope in my late teens. It was a very heavy instrument, quite unwieldy and it sat on a tripod which was angled at 52° so that I could easily follow the path of the heavenly bodies from my location in Holland.

Fast forward a few decades and from the comfort of my veranda I’m bringing in the Southern Hemisphere stars with a computer-controlled 90 mm Maksutov-Cassegrain telescope.

As this particular model is aimed at the beginners market let’s first explain a couple of basics. What exactly is a Maksutov-Cassegrain telescope?

It’s all about how you get the best optical performance in the smallest possible package by using various lenses and mirrors. So it’s not quite smoke and mirrors that will give you a long focal length but an ingenious design.

Here is a picture and a quick paragraph how it all works:

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“Mak-Casses” are primarily reflecting telescopes, but they use a corrector lens to eliminate aberrations that would result from the mirror design alone. In a "Mak-Cass” the incoming light passes through the Maksutov corrector lens (sometimes called a meniscus corrector, because of its shape) at the front of telescope. It is reflected from a concave primary mirror at the back of the scope which focuses the light to the front of the telescope where it is reflected again by a smaller, convex secondary mirror. Finally, the light travels back through a hole in the primary mirror to the rear of the scope where an eyepiece is located for visual observing (or a camera for photographing). By folding the light in this manner, a Mak-Cass can be made much smaller than an equivalent Newtonian or refractor telescope.

So you end up with a very compact but powerful system built by a company which has a great reputation when it comes to building telescopes.

Meade currently has three models in ETX Observer range: the 80 mm, the 90 and the 125 mm.
The ETX 90 sits at the sweet price point of just under $900 Australian so let’s have a look what you get for this.

First Impressions
This telescope may be compact but it comes in a big package for triple protection.
First you have the outer carton, then the display box and inside that an aluminium case for the actual telescope and a canvas bag for the tripod. Unboxing this feels like exploring Tutankhamen’s triple sarcophagus....

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Having the aluminium case and a canvas bag means this system is eminently transportable so it’s easy to set up in the middle of a big field or on top of a hill or to use it as a terrestrial scope. I am impressed with the quality of not only the way it is packaged but particularly with the way this telescope is built. The tripod is extremely sturdy and easy to set up. The telescope itself, being compact, is not lightweight and there is nothing flimsy about it. It looks like it is perfect for fieldwork. It comes equipped with two high-quality eyepieces, one with 48x magnification and the other 129x.

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A sizeable “handbox” which plugs into the mount drives the system. It has a database of some 30,000 celestial objects and a built-in speaker so the moniker “AudioStar” is well chosen. More on this later.

Assembly
There is a 50 page illustrated manual which makes it sound daunting to set up and use the system but half the manual refers to the ETX 80 model and it also includes some pages on basic astronomy.

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The whole telescope can be set up in about an hour and there is nothing difficult about it. What takes a bit more time is aligning the telescope by setting it to its home position so that it can automatically locate and track objects in the night sky. The key thing is finding true North or even magnetic North and the telescope will know how to compensate for the difference between the two. And here is where I found the manual to be directed mainly to a northern hemisphere audience with reference to the Polaris or North Star...

Every telescope needs to have a good viewfinder because the field of vision of the main scope is very small. The so-called “Red Dot Finder” gives you a wider field of view and in the middle of that you have a red dot light which can be adjusted for brightness. This is a very helpful accessory when it is aligned correctly.

The AudioStar
Most human beings can only see about 6 or 7000 celestial objects on a clear night away from artificial lights. The AudioStar has at least 30,000 objects in its database and because of its light gathering capabilities the ETX is able to pull in many thousands more.
This handbox has a two line LED scrolling display which I did not find particularly easy to use. For starters, scrolling is a bit slow and it has the feel of technology from the 90s. Obviously you need red light so that it doesn’t impact on your ability to see the fainter stars but I just wonder if a larger touchscreen display with the proper filter would not be a much better option. I use apps like Twilight on my phones and tablets for reading at night and that works quite well.

That would also make navigating through the menus a lot easier and an additional bonus would be that the display could also bring up a much larger segment of the sky that you’re looking at. You have to remember that these types of telescopes have a very narrow field of vision. It is great for looking at the moon, the planets or nebulae so a display, similar to SkyMap from Google would be extremely handy.

 


Stars, Camera, Action!
After aligning the ETX 90 with North you can then command the AudioStar to go to certain objects in its database. After that it can follow that object both horizontally and vertically as the heavenly bodies seemingly make an arc around the sky. That is quite handy particularly when you’re watching the moon as it is surprising to see how fast it disappears out of your field of vision.

The wow factor is high when you show others the craters on the crescent moon. The ETX 90 can accommodate a DSLR or any 35mm camera through the rear photo port. The adapter for this is an optional extra and was not included. So I had to improvise a little bit by holding my Galaxy S7 phone over the eyepiece to try to get a shot. Not very professional but the result gives a little bit of an idea what the scope is capable of.

 

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The fuzziness at the bottom is just a function of holding the phone at a slight angle... The moon also looks like it is shown in its entirety but it’s the edge of the viewfinder!
Another picture down below shows Jupiter and four of its biggest moons taken by the same means.

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Preliminary Findings
The Meade ETX 90 is a great scope for beginning astronomers. The way you can find your way around that big sky is greatly helped by the AudioStar. It can even give you a guided tour on celestial events for that night.

Its portability and ruggedness gives it a versatility in where you use it and how you want to use it. It is also great for terrestrial observations and photography.

Have a look at Tasco’s website who are the distributors for Meade Instruments in Australia. 


Check out this model for under 900 Aussie bucks or any other telescope within your budget range.

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