At first blush, the Celestron Ultima 2000 8 inch diameter Schmidt Cassagrain telescope looks pretty pricy for what it does. This telescope was available from mail order houses for $2700. Celestron sells the same optical tube as the G-8 on a very good equatorial mount which retails for $950 if you look around the web. The current NexStar CPC series is around $2000, but none of these have the push-to-object trick this scope does. More general information on getting a telescope is in my article on Picking a Telescope. So, I for one was wondering what it could be that would make this worth the additional cash.

Then I had a chance to use one at an astronomy club meeting.

This review is organized as follows:

Background on GOTO telescopes
Using the Ultima 2000
Optical performance of the Ultima 2000
Notes about photographic use
Concluding comments

Background

A GOTO telescope is called a GOTO telescope because it has the ability to automatically go to to an object the user selects on a hand computer pad. The mount has electreic motors to move the telescope tube as well as track objects as teh slowly move across the sky due to earth's rotation and their independent orbital motion. The GOTO telescope evolved from successive generations of electronically driven telescopes which started appearing in the early 1980s. The first telescopes with digital computers had encoding devices to tell the computer the telescope's orientation, but required the mount to be equatorially aligned with earth's pole (so one drive mechanism could counteract earth's motion). As technology improved, it became possible to build telescopes which could have their mount in other orientations and control the telescope to follow objects across the sky using two motors. At this point, people didn't need to point the telescope mount's hub at earth's pole to track objects across the sky. The Ultima 2000 was one of the first telescope and drive mechanism systems able to do this. Most modern GOTO telescopes are capable of automatically tracking the moon, stars, sun (You must use a full-aperature solar filter!) and planets automatically.

Using the Ultima 2000

Most people looking for a telescope as powerful as this one will run across similar products offered by Meade such as the LX200 driven telescopes they sell, or Celestron's NexStar 8 digitally controlled telescopes, which sell for about $800 less than the Ultima 2000. However, there are some very big differences in capability between these different telescopes which should be considered before making a purchase.

The general operating concept behind a GOTO telescope is that it should be able to show you the wonders of the heavens even if you only have a very basic knowledge of astronomy. These telescopes have simple methods for setting them up so they know where they are and can track objects. In the case of the Ultima 2000, you point the telescope north when you turn it on and input the date and time. Then the telescope will ask you to point it at two bright stars such as Sirius or Vega which are easy for a beginner to find. What the user does then is look through the telescope after it has roughly pointed at each star and manually center it with the electric push-buttons on the control pad. After this, you enter the star as centered and the telescope is ready to start tracking.

Now, here is where the Ultima 2000 really shines- it's just easy to use. To find an object, you can go through the menus on the red lit hand controller, or you can do something other GOTO telescopes simply do no t allow- move it by hand. Unlike the LX50, LX200, or NexStar, it is possible to reposition the Ultima 2000 by hand (the NexStar 8, though similar, does not move at all without electrical power). It is possible to *move* the meade telescopes by hand, but doing so causes them to lose their orientation data on the sky, so they can't track on whatever object you move it to.

With the Ultima 2000, there is a large handle on the telescope itself and it has adjustable friction clutches on the drive. If you see something in the sky and just want to look at it, just grab the handle and point the telescope at it. Now here is where the neat part comes in- not only does the Ultima 2000 maintain its reference so it can continue to automatically move to new objects, but it will instantly perform tracking calculations and track the new object in the sky, even though the tracking solution may be in the opposite direction and quite different from the last object! I believe the best part of astronomy is the moment of personal discovery- the Ultima 2000 may be capable of automatically moving to 10,000 objects, but it's also lets you do your own thing.

As for tracking accuracy, the telescope was dead-on for everything I looked at after programming it in. Only a small amount of adjustment was needed. The objects always appeared in the field of a 26mm eyepiece. However, the treat was finding the tracking accuracy- after going to look through another telescope at something the group of us were talking about, I came back to the Ultima 2000 to discover it was still dead-on target after half an hour.

The only problems I saw with all of this was the handheld controller either has to stay in your hand, or you need to stick some velcro to it and to the mount fork so you can put it down. The telescope drive system is extremely quiet. If you have heard the Meade ETX series, LX50, or LX200 in operation, you were probably struck by how much they sounded like an electric RC car. The Ultima 2000 is so quiet that if you are talking to other people, you will miss the sound of the drive.

The telescope can operate on AA batteries or a power cord attached to a source such as a car battery or an AC power converter. The batteries are cord free, but you'll only get a few observing sessions out of a set, or only a full night if you are staying up. On the other hand, a power cord is easy to trip up on, so you will need to give this some thought. The mount has a special non-wire wrapping routine built in for movement so that it won't wrap a power cord around itself as it operates. This is a good idea, but it sometimes looks odd since the telescope sometimes has to take the long way around to get to an object to prevent wire wrap. I don't know if this mode can be turned off or not, though.

Optical performance of the Ultima 2000

The Ultima 2000 is built around the time-tested celestron C8 8" f/10 2032mm focal length telescope. This telescope has been in production in one form or another since 1970, and so Celestron has essentially made this optical tube their flagship telescope. Because so many of these have been built, there are huge numbers of accessories available for these telescopes, and the Ultima 2000 has the bosses on the tube to allow you to attach secondary telescopes or other equipment. The telescope is built to be a general purpose instrument capable of showing something both at high magnification and relatively low power wide angle use. A focal reducer is available which will pull the focal ratio down to f/6.3 to put a wider patch of sky in the field of view. The telescope produces beautiful views of Jupiter, Saturn, and other planets, as well as bright views of nebulas.

However, as a general purpose telescope, one should remember the planetary views will not be quite as sharp as what a dedicated high end APO refractor or high focal ratio Newtonian or Maksutov can produce. On the other end, the telescope has a bit of difficulty embracing the full vista of large nebulas such as the Orion Nebula which low focal length Newtonians and refractors can capture. But given the fact telescopes specifically designed to excel at either of these listed tasks are virtually guaranteed to fail miserably at the other end of the viewing spectrum, which the C8 tube most certainly does not do. This telescope was designed to be a good telescope if you only owned one, and it has done quite well in that regard for thirty years.

The optical tubes shipped under the Ultima name appear to have been selected to be the best examples Celestron could produce. The Ultima 2000 produced views of Jupiter which were only slightly improved upon by a 6' f/14 refractor. Out of 20 telescopes, the Ultima 2000 may not have had the absolute best view, but then again the telescope that did cost nearly twice as much and weighs nearly three times as much. The only complaint I had was the truncation of the Orion Nebula. I had brought a 40mm wide angle eyepiece with me, so it was possible to get most of the nebula in the image, and that which was available was quite bright, but I expect the focal reducer is a must-have to do serious nebula and galaxy observing.

Notes about photographic use

The Ultima 2000 is capable of being used for high-end astrophotography. However, unlike visual use, the simple alignment isn't suitable for photography because objects will appear to rotate as they cross the sky. to prevent this, you have to either install a wedge between the mount and the tripod so you can align the central hub with earth's axis, or you will need to install a piece of equipment called a field derotator which counteracts earth's motion for the camera image. Given that the equatorial alignment makes guidance tracking easier, I would suggest this approach instead of derotating the field which requires the photographer to continuously track drift in two directions.

The Ultima 2000 has one significant difference from the inexpensive G-8 in that the secondary mirror in the center of the front corrector plate is housed in a cell which can be removed. This makes it possible to install the Celestron Fastar imaging kit which included a lens and camera mount. This makes it possible to install a digital CCD camera in place of the secondary mirror and thus use this telescope an incredible f/2 focal ratio for very wide field of view photography. Unfortunately, the telescope cannot be used visually when this conversion is done. Therefore, it would be necessary to mount a secondary telescope of some sort on it to serve as a guide scope for what would now be a powerful computer-guided astronomical camera.

Concluding comments

The Ultima 2000 is a lot of telescope. Is it worth the money? Well, that's something I've been asking myself. I've been thinking about getting a larger telescope, and there are some considerations I've discovered in the way of a purchase. I keep coming back these points in regard to having such a complete and perfectly packaged capable telescope which a prospective user should consider:

(1)The total assembly is a bit heavy- about 45 lbs. as well as being large. I saw it transported by pointing the tube down, folding the tripod legs together, and just laying the whole assembly down in the back seat of a Suburban (it filled the back seat). It may be too dificult to move around and set-up to get regular use. If it is in regular use, its appetite for batteries may quickly become annoying.

(2)The mount is one-tube only. The Ultima 2000 mount is for use with the Ultima 2000 only- any other gear must attach to this telescope tube. Other telescopes such as the G8 have an equatorial mount with a universal mounting head which can be outfitted with electric drives, position encoders, and a computer. The Ultima 2000 does GOTO operation and a lot of things the G8's CG-5 mount will never do, but there are a huge number of telescopes which can be swapped out on the CG-5 mount. In short, if you just love the general purpose C8 and want to use it all the time, the Ultima 2000 may be perfect. If you have a bunch of tubes for specific purposes, another solutions may be called for.

(3)Are you sure you want the sky handed to you? Something I remember from my early experiences in astronomy was pointing a telescope by hand at what appeared to be the brightest star in the sky the first night I had it out and discovering amazing Jupiter and its moons. There is nothing quite the same as finding something for yourself. In a way, the experience makes it yours in a way that having it shown to you cannot. I really recommend giving this point some thought if you are considering a telescope for a child. Something smaller, (I strongly suggest you don't go below 80mm in aperture) more portable, and hand-guided can lead to many experiences where some of the most incredible objects known can be found from your back yard and create bonds and memories that watching a machine guide to known objects simply isn't a substitute for. If, on the other hand, you have a lot of experience observing, the Ultima 2000 can take a lot of the bother out of finding objects again.

So, when I have to summarize the Ultima 2000, I have to say yes, you are getting your money's worth.

Recommended: Yes