Ten Reasons the ETX 90RA is the Greatest Telescope in the World (updated 6/23/12)

What would make a telescope the greatest telescope in the world?

Well, if you lived in a dark spot and had a permanently mounted telescope, it might be based purely on aperture. To others who had to travel to a dark spot, it could be a combination of portability and aperture. To other still; go-to capability might be the most desirable feature. Other considerations could be: price, limited storage space, size of transport vehicle, how cumbersome to set up, simplicity of operation, or a desire for it to be airline transportable. If you were intending to do a lot of public outreach, you would definitely want something that was robust! There are about as many different considerations as there are telescopes. Its a very subjective thing.

So, what would make one telescope in particular stand out above all the rest…? That is going to depend entirely on what you want to do with the equipment.

There are many well written web articles on this. All you have to do is search on “How to choose a telescope” and start reading. Again, you will find they all have a similar set of things to look at and, in the end, they all tell you that this is very personal and subjective thing.

What I’m going to do here is show you the things that are key to me, presented, more or less, in order of importance. If you want, you can use this same outline and see what you come up with. I’ve seen folks create complex grids based on different criteria, some even with different weight factors, to compare different telescopes numerically in an effort to clear the fog of purchase indecision. If that helps you, then by all means go for it. This example is less complicated but will still illustrate how to develop a structured process to evaluate a telescope.

To me, the Greatest Telescope in the World has the following traits:

  1. Good optics

  2. Enough aperture to keep you from being bored

  3. Easy to use

  4. Ability to track objects

  5. Easily transported

  6. Great grab-and-go

  7. Public star party resistant!

  8. Widely available

  9. Good support from vendors and user groups

  10. The one that gets me under the stars the most!

Now, I own – and use – more than one telescope. I also have access to some pretty fabulous club equipment that I get to play with several times a year. IMHO the little ETX stands out far above the rest because of the reasons above. Let me compare the ETX 90RA against the list and see if you agree.

1. Good optics

This is unchallenged by anyone who has ever compared the views presented by one of these scopes to any other scope. This inherently slow Maksutov has a well deserved reputation for good contrast, minimal image shift, and an ability to hold collimation well. They take a while to get to ambient, but this is a small price to pay for the pin-pointy stars that show up after about 45 minutes. (They will not be there before then!) Expect things to soften up much above 200X. Here in the Southeast there are a few nights that support 250X in this little scope, but they are rare. My favorite eyepieces are a UO 7mm ortho, a 12.5MM Celestron Ultima, the ubiquitous 26mm Meade SP, and a 35mm Celestron Ultima. I have a 5mm UO ortho which I use from time to time on some tight double stars. But it stays in my kit more than the rest. I’ve got to point out that a borrowed Televue 13mm Ethos showed the best images I have ever seen with this scope! The marketing hype in this case is not hyperbole! This eyepiece is almost as big as the little ETX, however, and does require some additional logistics. 🙂

On nights when the atmosphere cooperates, the images of the moon and planets are nice and sharp in the ETX 90RA and the good contrast mentioned above helps reveal faint objects against a very black background; objects that simply are not there in less contrasty equipment. When compared to a Questar 3.5, the image is very close. The edge goes to the Questar. The Questar is simply incredible and except for traits 7 and 8, would be my choice for Greatest Telescope in the World. I’ll explain more when I get there.

2. Enough aperture to keep you from being bored…

I consider small aperture anything less than 105mm. Medium aperture – again, to me – is from 105mm to 320mm. Large is somewhere between 32cm and 75cm. Anything above that is strictly OMG class.

Now, I want you to check me on something here. Is it me, or does it seem that there’s a lot of talk about what you can see with the medium-and-up classes of telescopes, but when it comes to small aperture scopes, the focus goes to what you can’t see? The comments go something like, “you will soon run out of things to see.”, or “strictly for the planets, moon, imaging, and brighter Messier objects”. There are notable exceptions to this: Sue French of Sky and Telescope has a great book entitled “Celestial Sampler” that is primarily for the small aperture scope. There are others, but the field is definitely dominated by lovers of larger aperture.

I love the larger apertures too! But, I also appreciate the capabilities of their smaller cousins and I’m afraid there are people out there that believe they must have a huge telescope before they can appreciate the hobby. This just isn’t so.

A lot of people, when they first get into the hobby, concentrate on the planets and the Messier list. This is an excellent way to get started! The only problem is that they sometimes get bored of looking at the same things every night. They never take the next step and move on to all the other things there are to observe. Many also get frustrated with the view in the eyepiece. They thought that they would see magazine-picture-like views; instead there are only faint hints of something in the eyepiece that the more seasoned observers get all excited about.

Someone should have told them what to expect.

It should also have been explained that the atmosphere is often the limiting factor and not the instruments aperture. They should also have given them a little information on what they were looking at. An island universe that is 2.5 million light years away, and that you can see with your naked eye! That is incredible. With that information available, that oblong fuzzy shape with a smaller cotton tip like shape to one side, suddenly is a little more impressive in the eyepiece.

I have seen all the Messier Objects with my ETX 90RA, I have also seen a goodly number of the Caldwells that can be seen from my latitude. There are many many other things that I have seen in this little beauty. I will begin to log all of these in another article. Another important thing hinted at above will be an article on how to “see” things. This can be challenging and fun. Once again, someone needs to tell you these things so you won’t get frustrated.

Bottom line: you will not get bored with a small aperture scope.

You will see the phases of Venus, the rings on Saturn (before they flatten out relative to us!), the great red spot on Jupiter and also shadow transistions of its moons. You will see the ice caps of Mars when the planet is close enough.

You will see double and other multiple stars, some of them with striking color contrasts.

Globular clusters will not resolve, but they will be there and it will be fun estimating their angular size and comparing that to what’s listed in the catalogs. The open clusters with all of their different shapes and sizes will be there in the eyepiece along with the opportunity to catch occultations where objects get in front of, or occult, stars, planets, and asteroids.

Nebula also come in all shapes and sizes. Dark, emmision, reflection, and especially planetary – a special category of emmision. You will need filters in some cases, but these are there for the finding.

With proper filters you will see sunspots and faculae, the tile like features on the sun’s surface.

Many folks never even consider the moon! It is the “evil one” when we are looking for faint and fuzzy things, but it is also an observational gold mine of opportunities. A gold mine that does not require enormous equipment to appreciate. This is one of a handful of objects that changes from hour to hour! Shadows cast by the rims of enormous craters, bright emanating rays, rilles and mountain ranges, and libration, the rocking about the axis that allows you to see almost 60% of the moon’s surface! You could spend a very long time on the moon itself without growing bored. (Did you know there was a crater named “Birmingham”? Named not for my beautiful city or our namesake city in central England, but for an Irish amateur astronomer. I love stuff like this)

You will experiment with different eyepieces.

You will get good at estimating the “seeing” – how steady the atmosphere is – by taking bright stars out of focus and observing how the image moves.

Did you know that you can see Jupiter and Saturn in the daytime, as well as Venus and Mercury? You have got to be incredibly careful when you do this! We will have an article on this at a later date. Again, never look at the sun, or anywhere near the sun without very specialized equipment!

You can also see brighter stars in the daytime. Neat, huh?

You won’t be bored with a small aperture scope. Nope, not at all. Especially if you “focus” – that’s for you, Scott – on all the things that you can see instead of the things you can’t. 🙂

3. Easy to Use:.

Before getting to the ETX 90RA, let me make a quick comment about the telescopes available on today’s market.

Today’s telescope’s have never been more user-friendly!

The go-to technology on the high end will determine where you are on the planet, where North is, and will adjust for the tripod if it is not level. It already knows the date and time and will choose a bright star and then go to it. All you have to do is make minor adjustments and synchronize! Unbelievable.

At the entry level go-to, you will have to level the scope yourself, point it close to North, tell it where you are and what the date and time are, and then it will go to an appropriate bright star and wait for you to make any small adjustments that are needed. After that, it will go to practically any object you want.

If you want the same functionality without the more complicated (and expensive) motorized go-to ability, you can even choose a push-to capable scope. Here you go through the same data entry process as the lower end go-to scope, and then simply push the scope where it tells you to. When you look through the eyepiece the object will be there.

Again; unbelievable!

Reliability is good and this technology is getting very affordable too! More people are viewing more things with less frustration.

Times have never been better for amateur astronomy.

Ok. With all that said, who would want to revert back to the old manual method of finding things…?

Me. 🙂

I can make a few very weak arguments for manual over robo, but they won’t hold up. Your batteries will eventually run down (but you can still find things manually without too much difficulty, or just have a spare battery). I could say that the plastic gears will eventually wear out and be difficult to have repaired (but this does not seem to be the case. The blame things are very reliable). I can say that the go-to is noisy (oh, come on…). I can say that it will make you weak! And that you will not learn the sky (Ok, there may be something to this one, but it too can be overcome… 🙂 ) I can say that the manual model is much cheaper (this is just not the case. You can get a good go-to on the used market for not very much more than a good used manual model). Lastly, I can point out that the databases are not complete ( I don’t know what “complete” means, but there won’t be many objects missing from the databases. The only thing you might have to do is know the names of a few stars as well as their Bayer designation. You can also enter a number of “user defined” objects if need be.)

When it comes down to it, the only reason I can give you for manual over computerized object location (COL)….

Its fun!

I’m just twisted like that. To me its the challenge of finding stuff; enjoying the journey as much as the destination. Its one of the things about the hobby that I find so appealing. Its like solving a puzzle or riddle.

Out of necessity you will learn the sky quicker and this is a good thing. You can still do this even if you go robo, but it will take you longer.

You understand the hobby at a different level when you learn the sky. You will understand precession and visualize the First Point of Aries moving slowly Westward into Pisces. You will notice the planets as they retrograde (change directions and back up!) You’ll be able to look at a star chart and see your horizon and know which stars will be above it. You’ll notice the different colors of the brighter stars and you’ll know them by name. You’ll be able to tell the sidereal time without looking at a PDA or computer because you will know what stars are on your meridian and their Right Ascension.

Again, you can do all of this if you use COL. But you’ll find it harder unless you look up from time to time away from the eyepiece or the controller’s display.

Now that I got that out of my system, let me move my soap box to the side and get back on topic.

Just how easy is it to use the ETX 90RA?

Very easy! For two reasons.

First, because the ETX 90RA is a fork mounted telescope which means it’s easy to polar align; and second, because the ETX 90RA has very good setting circles – the only area where the ETX 90RA beats the Questar 3.5! I’ll cover both of these in detail in the article on “How to find things in the ETX 90RA”. If you want to get a jump on this, search on “Kochab clock” and read the excellent explanation by Dr. Clay Sherrod.

Two more things: you’re going to have to swap out the straight-through finder for a right angle finder. Next, you will have to learn how to use setting circles!

Stop the groaning. Neither one of these is hard to do.

A polar aligned scope has several advantages to an alt/az mounted scope. The tracking is now in one direction only, east to west. Alt/az mounts that tracks must constantly be moving in two dimensions, side to side and up and down. (This really isn’t a big deal but it is more complicated control-wise.)  Also, if you don’t want to use motorized tracking when polar aligned, you center a bright star in the finder and set the scope for the stars RA. If your polar alignment was good (and there’s no reason it won’t be) the DEC will be correct already. Since the stars take 23 hours and 56minutes (more or less) to travel 360 degrees (one time around), objects just coming into view in an eyepiece with a one degree field of view will stay there for almost four minutes (two if they were centered)! And this is for objects on the Celestial Equator. You will have longer for objects further north or south. Plenty of time to  find the next object without rushing.

The other most popular of the equatorial mounts is the German Mount. These are just as usable as the fork mounts but they are not as compact and require a little more effort ( but not much more) to polar align. All the advantages of the fork mounted polar aligned telescope apply to the german mount when it comes to finding and tracking objects.

All you need is your red flashlight, the coordinates for the objects, and a couple of star charts and your good to go! You’ll get to the point that you can get the coordinates off of the star charts directly well enough to find things. If you want to track the object all you have to do is turn the tracking motor on. The earlier Meade tripod, the 883, is superior for this, but you will need to take care concerning the collapsing leg problem, even though this was mostly with the ETX 125 and not the ETX 90.

Polar alignment is also superior for star hopping. The ETX 90RA excels in this. Here you don’t need to move charts around like you would to get the alt/az movement for the hop. The ETX 90RA is already set up to move in Right Ascension and Declination, just like the star charts are laid out! You’ll use this when finding really faint objects (I heard that! All objects are not faint with 90mm of aperture. 🙂 ).

You would think that the manual ETX would be quicker to find things and therefore you would see more objects in a single viewing session than someone using a goto scope. I have found that this is not the case. If you plan your session ( as all of you should) and have the objects listed in a logical sequence along with their coordinates, then you could see more objects because it takes you much less time to move from object to object than it does for the motorized scopes to slew from place to place at their relatively slow pace.

Actually it will take you longer. You’ll find yourself going from chart to sky to scope and back again to chart. And then back to the sky. You’ll spend more time looking up. Sad but true, robo-owners.

The puzzle solving thing may not appeal to everyone, but it does to me. Even if it doesn’t appeal to you, the fork mount and setting circles are easily mastered.

The ETX 90RA is simplicity itself – once you replace the finder and learn to use the setting circles!

You will find it worth the effort.

4. Ability to Track Objects:

This feature is not absolutely necessary to enjoy the hobby, but there are times when its nice. Especially at our club’s public star parties. On these occasions we have various objects set up in different telescopes at different stations. The people move from scope to scope and take in the moon, available planets, assorted deep sky objects, and usually a couple of double stars. We usually have at least one object in two or three scopes so that folks can compare the view with different magnifications or apertures. The flow of people is nowhere near as organized as this sounds! Everyone eventually takes a peek through all the instruments. The sequence may not be the same for everyone there, but they always start with the biggest ones first! The little ETX 90 is usually last. 🙂

For the telescopes that track, the objects stay in the eyepiece as long as there are people who want to take a look. For the telescopes that do not track, you will have to make adjustments every few minutes to keep the object in the field of view. Not a problem at all, but its nice to have the equipment do this task for you.

This feature is also nice  when viewing at high power. At higher magnification, the field of view is substantially smaller and the object does not spend much time in the eyepiece. We talked earlier about how an object on the Celestial Equator would take 4 minutes to transit an eyepiece with a one degree FOV (field of view). The ETX 90 series has a focal length of 1250mm and when using the provided Meade 26mm SP,  yields  1250/26 = 48X magnification. This eyepiece has an apparent FOV of 50degrees. The resulting FOV through the eyepiece is approximately 50/48  = 1.04 degrees. We’ll call that 1 degree.

Now look what happens if you use the 7mm UO ortho that I use for 98% of my high power viewing. Here, the magnification is 1250/7 = 179X.  This eyepiece has an apparent FOV of 45 degrees  and the resulting approximate FOV through the eyepiece is 45/179 = 0.25 degree. With this setup of telescope and eyepiece, the object will take only 0.25degree X 4minutes/deg = 1 minute, just 60 seconds! Not very long for you to take in any subtle features.

If your telescope is tracking the object, you can take all the time you need to look at it. This is one of the secrets of “seeing things” that we will talk about in more detail in a later article.

BTW, a very good explanation on eyepiece selection in general, can be found on the Televue website. Click on the “eyepieces” page. The information found here will explain why some telescope/eyepiece combinations seem to work better than others.

There are many telescopes available to the modern amateur astronomer that will track objects. Some of them do so with such incredible accuracy that long term  exposure photography and electronic imaging are possible; the resulting pictures rival those in any magazine. You will not be able to do this with the ETX 90RA! The tracking is more than good enough for visual use and also for some shorter time frame photographic and electronic imaging. The ability to stack multiple shorter term images can  yield some pretty impressive results, but there are other platforms better suited to this task.  None  will come in anywhere near as compact a package!

There you have the three reasons I think the Greatest Telescope in the world should be able to track objects: Its great for star parties, it allows you to “see” things better, and it will even allow you to dabble in imaging if you are so inclined!

The ETX 90RA fulfills all three of these needs.

5. Easily Transported:

I live in a very bright suburban area. There are monstrous malls, enormous car lots, huge athletic field complexes,  and sprawling neighborhoods galore. All of these are lit up like Christmas Trees most of the year. The concepts of light pollution and “dark sky” are totally unheard-of in these parts. Sadly this is true in more and more places. There is a natural conflict between the safety of the public and a dark sky. Public safety must be the clear winner, but there are alternatives to the wasteful excesses of the majority of today’s lighting design. Especially lighting dedicated to advertising, which should rank third behind safety and dark sky!  I am encouraged on this front because in addition to being bad for the amateur astronomer, these practices are expensive! Modern alternative lighting is getting cheaper by the hour in “light” of – another one for you, Scott – the rise in energy cost.  I believe our skies will show the benefits of this in the next generation or two. Go to “The Dark Sky Society”  and the “International Dark Sky Association” web sites for more information on this.

Ok. Soap box aside. Back on topic.

In the mean time, a lot of amateur astronomers are left with no choice but to travel to a dark spot with their equipment. This equipment includes more than their primary telescope. Folks take a couple of chairs, one or two tables, batteries, assorted charts, laptops, flashlights, coolers, food, coffee or other beverages, and cases full of eyepieces, filters, diagonals, compasses, and green lasers. Once more, this varies significantly between different people.  More and more, though, people are having to pack up all their stuff and travel and hour or so to get to a dark spot.

How easily this can be achieved depends on the transport vehicle, although even this is really relative to how creative you are. I have seen some amazing packing jobs! Two examples stand out.

The first was a gentleman I met three years ago at the Mid-South Stargaze at French Camp, Mississippi. His camping gear consisted of a two man tent. His telescope was a home built 10 inch truss dob. He had a small table, canopy for the dew and daytime, and a cooler and cooking gear. He packed all this along with charts and clothes for three days…. in an old MGB! I was totally impressed!

The second example is a more recent one where one of our more hardy club members traveled to the Chiefland Star Party in Florida. He drove there in his Toyota Prius. He carried with him: tents, canopy, ground tarps, chairs, tables, assorted red lights, food and drink, etc… along with his Obsession 18 inch UC dob! I love it.

I tip my hat to these two gentlemen! They take “easy to transport” to a whole new level and illustrate that “easy” does not automatically exclude “large” .

On the other end of the “easy to transport” spectrum is  my ETX 90RA. I have the telescope, two or three eyepieces, some filters, extra batteries, table top legs, my worn copies of Pasachoff and Sinott, a level, a right angle screwdriver, and a small red light – all in that tiny blue bag with the Meade logo on it! I call it my “observatory in a bag”. I have the original 883 tripod in another blue bag. I grab the bags along with a small table, a couple of chairs, a seasonal beverage and some snacks; and I’m good to go.  A half dozen times a year I don’t even take the 883, I just attach the table top legs to the ETX and take advantage of a picnic table or other sturdy surface.

This particular arrangement has served me well on vacations, hikes, urban outreach trips, and numerous other sorties where “easy to transport” was defined by limited space, weight, short notice, or sheer laziness on my part!

A telescope that is easy to transport will get used much more. Again, this does not necessarily have anything to do with size of equipment. Smaller scopes are easier to move, but as shown above, they are not the only telescopes that are easy to move from one spot to another.

“Easy” is also in the eye of the beholder.   🙂

From any perspective,  the  ETX 90RA definitely meets my fifth requirement for the Greatest Telescope in the World!

6. Great Grab and Go

I love grab-and-go scopes! They are usually humble things, modest in aperture and features, and at first glance, not very capable when compared to their larger and better equipped cousins. But don’t be deceived by their meek appearance. On a moments notice you can take one of these scopes and turn a few spare minutes and a clear night (or day) into an observing session! What would have been a missed opportunity is suddenly time spent in the eyepiece. This is a good thing!

I’m a definite believer that even a short observing session with a smaller telescope is better than no observing session with a larger instrument. 🙂 This doesn’t mean I’m about to sell my larger scope and have nothing but small, easy to move ones. But it does mean that I think this capability is important enough to be included as one of the features that The Greatest Telescope in The World should have!

I’ve mentioned before that I live in a suburban environ and that I have to travel a good distance to find a dark sky. I don’t get to do that very often, so I have to take advantage of the skies I have. I could do this with a larger scope but, besides the “travel time”, the illusive “spare time” is also getting harder and harder to find. When I do get the occasional thirty minutes or couple of hours, I like to spend as little time as possible setting up and taking down equipment. A telescope that is completely set up and waiting on me in the corner of a closet or covered in the basement, and that can be moved easily, is perfect for my needs.

Another consideration for me is the lay of the land! When my bride and I purchased our abode, we were more concerned with school systems, driving convenience, kitchen layout, and a fenced-in yard. As much as I would have liked to have included “great observation site” higher up on the considerations list, it just was not meant to be. As a result, I have several “observing sites” around the house, depending on what I’m trying to see at the time. I have the front sidewalk and cul-de-sac (we used to call them “circles”) for views to the west. I have the driveway for views to the North, East and the Southwest, and I have the back deck for views of a goodly portion of the zenith plus a gap in the trees where I can get a sighting on Polaris. Any object lower than 100 in declination is hidden by the trees and a mountain to the South. Thank goodness Orion is a winter object in this hemisphere because the only way I can see it is through the trees!

If I did have a place to keep a larger scope set up all the time, it would be pretty limited by the terrain. As a result, the ability to move a telescope around helps me a lot. Grab and go is high on my list of desirable features.

There are many telescopes that make great quick-look scopes. Any number of short tube 80’s or other refractors in that range will do, the dobsonian mounted Newtonians under 8inches are about as straight forward as you get, and of course, the 90 to 150mm Cats/Maks in either manual or the more intelligent incarnations. All of these can be put into service in just a few minutes and the things you can see will keep you happy for a long time.

I’ve got to be honest… I have a 6 inch Orion XT that I keep set up in the basement that gets a lot of use! You take off the cover, grab the whole thing by a base mounted handle, and walk right out the door to the driveway. You can literally be star hopping in 60 seconds! The difference between 3.5 inches and 6 inches of aperture is pretty noticeable as well. As far as a quick look scope goes, its hard to beat; and if that was the only consideration, it would get my vote for the “Best Telescope in the World!”. As it is, with the other considerations, the six inch dob is relegated to “The Second Best Telescope in the World!” and I’ll talk about that in another article.

Although edged out by the six inch dob in the grab-and-go department, the ETX 90RA is still a great quick-look scope. As an example, earlier this week I stepped outside around 5:30am to a beautiful clear morning!

To my delight, the clouds had rolled out overnight instead of later in the morning as had been predicted. My ETX was already mounted on its tripod and all I had to do was set it out on the back deck. Leo has been getting higher over the past several weeks and was almost due South at that time of the morning. Saturn is just below Leo now and was in as good a position as it was going to get from the back deck – even if I did have to look through the trees. I mentioned earlier that the back deck has a good view of Polaris. It took me less than sixty seconds to get a “close enough” polar alignment (thanks again, Dr. Clay) and swing around to Saturn. Saturn is noticeably dimmer this year than in the past due to the rings being almost edge on; it was still a pretty sight, even at 48X. I sat there at the eyepiece for a long while just taking it in. While I was there, I checked my PDA and set the RA setting circles for Saturn’s numbers. Since I was in Leo I might as well check out M84/M86. I can see them on dark nights from this location… Didn’t see them. The sky was brightening up nicely. It was close to 5:45 by then, well past astronomical twilight, and sunrise was only 45 minutes away. I set everything back inside and was done.

That’s what a grab and go is all about.

The ETX 90RA takes up very little room. Even attached to its tripod, it is compact enough to be tucked away just about anywhere and not be under foot. It will sit there patiently and quickly be put into service for those impromptu opportunities. It fits the bill as a great grab and go, quick-look scope.

7. Star Party Resistant


Ninety-nine percent of all star party attendees are very conscientious when it comes to your telescope. They are super careful around your pride and joy, and wouldn’t do anything to damage it for all the stars in the sky. Occasionally you’ll find someone who is unusually obtuse when it comes to taking care of the belongings of others, but they really are rare and usually stand out.

The rest respect the equipment, but they are unfamiliar with it and usually during an evening you will have someone inadvertently grab the scope to steady themselves and it will go starhopping off into regions of space here-to-for unobserved. You can also expect the mount to be bumped, kicked, or brushed against with a similar result.

Other things can happen, too. If you don’t properly tighten the retaining screws; the diagonal, the eyepiece, or both, can be pulled out, scaring the pajeebies out of the little munchkin and their parents. Finders will come off too or at least need serious realignment. If there are buttons and switches, they will be pushed and thrown. The focuser will be unfocused and cords will be tugged on. Objectives and eyepieces will end the evening with fingerprints and you will occasionally hear the sound of velcro unvelcro-ing.

All this sounds bad, but it really isn’t. Seasoned Public Star Party cognoscenti expect these things and plan accordingly – and this planning sometimes involves the careful selection of which telescope to take to the party.

Don’t get me wrong; all scopes are star party scopes but, IMHO, some of them are easier to “party with” than others.

A good star party scope will flourish in the harsh environment which, believe me, is only partially described above. So what makes the ETX 90RA a good star party scope?

First, the ETX will track the object. This is more of a nice-ity than a necess-ity but it is kind of neat for the scope to do the job for you of keeping something in the eyepiece for the folks to look at. Now, I have an Orion XT6 dobsonian that I believe is the best star party scope in the world even it it doesn’t have tracking ability. I’ll go into this in more detail another time. I still consider the ETX to be the overall Greatest Telescope in the World because of all the other areas where, again IMHO, it surpasses the Orion. Even in the star party arena, another thing that the ETX does better than the Orion is that it is more “nudge and grab” resistant. By that I mean that it has pretty good RA and Dec clutches that lock the scope on the object when its tracking. Its not likely that someone who inadvertently grabs an eyepiece of the back of the scope will knock the scope off the target. The ETX also has a natural place for folks to place their hands if they have to. This is something I go ahead and tell people who want to take a look through my scope. The forks of this smaller fork mounted scope offer a great place for people to lightly steady themselves and make it much less likely to throw the object out of the FOV.

The clutches will slip if they need to. This is desirable as it minimizes the opportunity for damage to the RA and DEC controls.

Like I just said, the clutches will slip. When they do, it is easy to get the ETX back on the object. You simply reset the DEC setting and swing the tube in RA until the object is back in view and then set the clutches for the tracking motor to begin its work. To make your life easier, go ahead and get you one of those inexpensive folding step stools that has an extension above the top step. This gives the kids a place to steady themselves.

Also, as we have discussed before, the ETX is easy to get polar re-aligned when it gets the occasional kick or bump from either one of the party goers or you trying to prevent a party goer from doing the same thing!

One more thing to mention… be careful when lowering the scope. You will be tempted to take the scope to the kids – in other words to shorten the mount. Don’t do this. When you shorten the legs you narrow the base of the tripod. You now have some center-of-gravity issues to deal with. It is much easier to topple over. Always take the kids to the scope, not the other way around. Go ahead and get one of those nice sturdy step stool or short step ladders like the ones we mentioned above.

Another nice thing about the ETX at a star party is what I call “walk-off-ability”. This means how easy it is for you to walk around the star party when things are slowing down and leave your scope all alone. 99% of the time you will be near a good friend who will watch things for you if you walk to the other end of the field for a few minutes. Also, if you simply put a scope-cover over the equipment its not likely that anyone will bother it – but have your friend keep an eye on it anyway:) .

The ETX 90RA can still be found on the used market in great shape for $250 or less. A good Questar, on the other hand, will cost $2500 and up… Food for thought.

Lastly – kids love it! Sometimes I set up a very sturdy six foot folding table and have star charts, magazines, and club information for the party goers to peruse while they are waiting for an opening at a larger scope. Usually when I do this, I will set up the ETX 90RA on its table top legs and set it on the end of the table where I’m sitting. The kids always light-up in a big smile when they see a scope that is just their size! All the attributes mentioned above still apply to the scope when it’s table-top-mounted. It tracks great, is still sturdy enough for them to actually touch, and its easy to get back on target when it gets scooted off the object. I do admit that in this configuration I don’t do the “walking about” that I would do if the ETX was perched upon its tripod.

To summarize: The ETX is a telescope the people can actually touch and still stay on its object. When they touch a little too much its easy to get back on target or re-aligned. And it tracks. Its not so pricey that you worry too much, and lastly, the kids – and a lot of the adults – think its cute!

Don’t worry about its plastic parts either. They are a lot more robust than some reviewers would like you to think.

The ETX 90RA thrives in the star party environ!

Reason number eight: Widely Available.

 Hmmmm… This particular reason is going to get more difficult to justify, but for the time being is still valid.

 The telescope was introduced in 1996 and was an immediate hit with the amateur astronomy crowd. The initial manual configuration was replaced in early 1999 by its more intelligent sibling, the ETX 90EC. The EC model had encoders, servos, and an optional controller that could reliably slew the telescope to just about any object for you. And it would do all this for the same price that the first version sold for when it was introduced! Not bad. As a result, the initial versions – Astro, RA, and M – were heavily discounted and the existing stock was soon depleted. This is when I purchased the one I still own for only $170.

 Contrary to those who have condemned this plastic scope to a short life, there’s a lot of these original scopes still out there. These little gems can still be found on the astro classified websites with surprising regularity. The price at this time, usually including a tripod and a few other accessories, is still under $200. I just checked and between Astromart and Cloudy Nights there were ten of these offered for sale over the past few months. If you open the field up to all versions of the ETX 90 you can add another twenty scopes to that number.

 The original version will be more difficult to find in the years ahead, but for now you can still get your hands on them!

Coming Soon: Good Support from Vendors and User Groups


Reason Number Nine: Good Support from Vendors and User Groups/treatment for Telescope Fever

When someone  is considering getting a telescope it is usually the result of Telescope Fever.

Telescope Fever is a malady that has only two known cures: the actual purchase of the equipment, or a sobering review of one’s bank statements. In some instances the bank statement review only delays the onset of equipment purchase.  Telescope Fever dulls the senses and causes obsessive fixations on usually a single piece of equipment and two questions:

1. What can I see with it?

2. How much does it cost?

(A variation on number one is: How many bells and whistles does it have?)

The person at this point is totally immersed in telescope review sites and flashy magazine articles – usually ignoring the more negative comments because secretly they have already made up their minds. They might wait for a star party and actually look through one of the scopes they are considering, but this is pretty rare and goes against traditional “telescope fever” protocol.

The telescope is purchased and delivered and only then do the symptoms of “telescope fever” begin to subside. The head clears and additional questions begin to surface:

3. How do I put this thing together ( the instructions are usually lacking in one or more areas)

4. How do I operate this thing once I do put it together?( crew-served telescopes are not unheard of)

5. Where am I going to store this thing? (perhaps a large barn?)

6. How am I going to move this thing to a dark site? ( Check the GCVW specs on your tow vehicle)

7. Where’s the rest of it?  (Didn’t all those accessories shown in the magazine come with the base package?)

8. Who can I talk to about all of this? ( The factory?…. the high end scopes usually have great factory support, …the others?)

The answer to question No. 8 usally leads to the answers to the other questions. This is where the vendors and users groups comes in.

Lets discuss the user groups first.

The most comprehensive source of information on the ETX series has got to be Weasner’s Mighty ETX Site. Here you will find history, technical tips, equipment fixs, recommended accessories, and realistic observation reports. This and more. If you have a question now, someone else has had it also and it was probably addressed on this site. Great resource.

Another site is Cloudy Nights Telescope Reviews forums section. In the Telescope Specific Forums section are hundreds of posts from ETX owners addressing, again, the myriad of questions and comments that owners and would be owners have posted.

I need to mention the different Yahoo Groups for the ETX series, Start with the ETXASTRO one and go from there.

There used to be a good one on Astromart but since they began charging folks they have also limited the number of posts that you can review.

These are the ones I’ve used the most, but there are others.

These sites all have search capabilities that make a specific topic easier to locate.

When it comes to vendors you can find anything from finders, eyepieces, accessory trays, adapter plates for different mounts, dew deleters, solar filters, and camera adapters. The best way to locate these is from the different internet sites mentioned above. All of them have links to the vendors.

If there is an accessory that could improve the ETXs use or a modification that would enhance its performance, I guarantee that someone has probably come up with it and that its well documented – good and bad – on one of the forums or user groups. You’ll also find numerous other sites dedicated to the ETX listed on the above mentioned websites. Begin with the ones mentioned above and you can spend hours researching just about anything related to the equipment or how to use it.

You can also still find parts for the older ones. Even the ETX Astro like mine. A quick search on Cloudy Nights or Astromart can find all sorts of things.

A lot of these scopes have been made and sold and resold. Contrary to some of the “large aperture only” commenters and articles, there are an awful lot of folks who have used and still do use this equipment.

Lots of support for this little scope, and that’s reason number nine why, for me, its The Greatest Telescope in the World.

3/18/2012 PM


Reason Ten – The telescope that gets me out under the stars the most!

This is the most important of all the ten reasons.

Using a telescope is – to some people at least. Me, among them. – an important part of the hobby, but not the most important.

The most important thing is just being out under the stars. Learning the night sky. Appreciating how it changes from hour to hour, from day to day, and from season to season. Ekeing out the subtle differences between the colors of the stars. Knowing that its about to dew up by the feel of the air. Anticipating the constellations that are about to rise. Observing a planet as it moves from night to night. Appreciating the shadows on the moon and the movement of Jupiter’s moons. Knowing that a friends battery is about to go dead by the sound of servos. Hot coffee, cold sandwiches, finding a comfortable chair. Arguing about the best eyepieces and how many stars can be seen in the trapezium. Watching a kids face when she sees a tiny crescent Venus. Listening to an adult gasp as they look through a telescope for the first time in their life and see Saturn’s rings. Listening to how quiet it gets when everyone around you is either asleep or intent on the view. oohing and ahhhing as a skimmer  moves across the sky leaving a glowing train behind it before bouncing back into space. Warm feet on a cold night. Asking and answering questions as you share when others are around and wondering what that is thats walking around when your by yourself. Getting an inkling of how big all this is and your place in it. Wondering about all the millions of variables that had to line up for you to be here at all to take it all in. Frowning as a neighbor turns on a back porch light. Smiling as you realize the transparency suddenly improved.

These are some of the really important reasons I’m into the hobby and the ETX 90RA has without a doubt been my observing partner on more nights than not. It has turned an extra  hour when there’s nothing on TV into a something to blog about. Its easy to set up and the things it does well far outweigh what it does poorly for my money. I won’t hesitate to set it up for a quick look if the skies open up for a hour or the sucker-holes are large enough and moving slow enough that I can get a peak at something interesting. My larger scopes – yes, I do appreciate larger aperture – won’t get set up unless the conditions are much more promising and I have more time.

I’d have missed a lot of stuff if I had a telescope other than the ETX 90RA.

It is the one that has gotten me out under the skies the most.

Now I’ve got to be honest with you. Since I got my Questar it has just about replaced the ETX90RA on a lot of nights. It is in a whole different league when it comes to ease of use and the views really are better – although not by as much as you’d think. All that said – there is a relaxed attitude that I have with the ETX90RA that I haven’t quite attained with the Questar just yet! I am just a little bit more puckered up as I set the Questar up or change eyepieces. I’m also hesitant to walk away and chat with someone down the line. I predict I’ll get over it 🙂 .

I said earlier on that the ETX 90Ra is the one scope that has stayed while the others have gone – although the Q appears to have staying-around potential. The ETX90RA  is always there in its blue bag with a 26mm and 12.5mm Meade SPs and a 7mm UO Ortho. There’s a red light, an OIII filter, and an Orion DeepMap 600 along with the table top legs and some extra batteries. All you’d need to observe to your heart’s content.

I will use the ETX still from time to time. I’m going to do one of those compare-it-to-the-Questar write ups one day.

It has shown me many things and given me an excuse to be outside when I thought I needed one.

It really is the greatest telescope in the world.


June 23, 2012 PM

3 thoughts on “Ten Reasons the ETX 90RA is the Greatest Telescope in the World (updated 6/23/12)”

  1. I have an ETX90 M model, which is a newer version of the RA. I love the optics, and the mount, simple as it is, works better than one might expect. But I do worry about the longevity of the mount. Have you any comments on that?

  2. Hey there, Larry.

    The only negative comments I have had relating to durability are concerning the finder on the Premier Edition series. They do not suffer abuse well and tend to break off. I installed the right angle modificiation early on and that finder has proven to be sturdy. I have had my RA for over ten years and it has been used a GREAT deal. The only issues I ever had required me to reposition one of the small teflon pads that the RA mechanism rides on. The view would hesitate and skip along until I fixed that. I have found them quite durable and my particular example has survived many tugs and grabs at star parties.

    Good to hear from you.


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