Scoping Out the Options for the Starry-Eyed
By RONALD D. WHITE
TIMES STAFF WRITER
October 11 2001
For years, they beckoned, tucked between National Geographic magazine adventures. They were advertisements for telescopes of varying sizes with odd hand-held devices and outrageous promises attached.
"The rings of Saturn, the Orion Nebula, the Andromeda Galaxy or any one of [thousands of] other celestial wonders stored in the Autostar hand controller's database," one ad promised. "Select an Object, press Go To, and watch as the [telescope] moves to the object, places it in the field of view, and tracks it across the sky-- automatically, first time, every time! "
How does the boast of instant celestial gratification and near idiot-proof deep-space observation turn out under real-world conditions? To find out, we went to the two dominant players of the "go to" telescope industry, Torrance-based Celestron International (a division of Tasco) and Meade Instruments Corp. in Irvine. We tested the $1,695 Meade LX-90 and the $1,399 Celestron NexStar8. Simply put, these telescopes have the ability to find and focus on any of thousands of celestial objects automatically. It had been 30 years since my father brought home the little 20-power telescope that I used on the roof of our family home almost every night. Because the spotter scope alone on the Meade was more powerful than that, I knew I would be awed by a clear view of the Ferris wheel on the Santa Monica pier and perhaps would not be the best judge of what I would be seeing. So I coaxed a husband-and-wife team of UCLA astronomers to give up a Friday night and put the instruments through their paces.
There are three basic types of telescopes: reflectors, in which the lens piece is located near the front of the scope; refractors, in which the eyepiece is at the end of the scope; and schmidt-cassegrains, in which the eyepiece also is at the end but works with both a primary and secondary mirror. Amateurs can recognize a schmidt-cassegrain from its short, stout appearance. Both scopes tested are schmidt-cassegrains.
Both the LX-90 and the NexStar8 gain their power from their 8-inch apertures. The larger the aperture, the more light gathered by the scope. The greater the light, the more likely that a distant star cluster will look like individual points of brightness instead of a milky smudge. Moving up from a 6-inch lens to an 8-inch, for example, is not a straight mathematical progression but one that offers a 70% increase in light-gathering ability.
The genius in these instruments comes from their electronic drives, their computers and their databases of celestial objects ranging all the way from the nearby solar system to "diffuse nebulosities."
For the Meade, it's the Autostar Hand Controller, which, for this telescope, also includes the coordinates for 30,000 celestial objects. You simply plug the phone-style jack into the base of the telescope, flip the "on" switch, then sit through the obligatory warning against looking through the lens at the sun. The telescope has to be level and pointing north. Unless you happen to have an astronomer on hand, you'd better bring a compass.
You are required to enter the date, time and daylight saving status. For location, you can key in any of several jurisdictions that are included in the database. The latter is an inexact step for both the Meade and the Celestron, but more on that later.
At that point, you're ready for business. The next screen asks whether you want an easy alignment. It will then choose a star, perhaps Vega or Sirius. Suddenly, the computer is sluing, or turning, in that direction. Then it focuses automatically.
The NexStar hand controller works in similar fashion. Better backlighting makes it a bit easier to read at night. But where the Meade simply requires you to punch in your current location, such as the Mount Wilson Observatory, the NexStar requires you to punch in latitude and longitude numbers listed in the owner's manual.
Here's the inexact part for both controllers: The alignment star chosen by the telescope should now be visible through the eyepiece of the telescope. You are required to center the star in your field of view; then you press enter again. The telescope then looks for the second star for the two-star alignment process and tells you to follow the same procedure.
The component that most affects your field of view at that point is the eyepiece. Telescope eyepieces work in reverse compared with camera lenses. Moving from a 26-millimeter lens to a 50-millimeter lens in a camera gives you a tighter, closer view of the object. In a telescope, it's the opposite.
The NexStar8 comes with a very forgiving 40-millimeter Plossl eyepiece with a wide field of view, meaning that your alignment star will almost certainly wind up within your sight. But so will other stars, particularly if you're in an area with little light pollution.
The rank amateur can have a difficult time figuring out which star to center. The Meade comes with a 26-millimeter Plossl, leaving fewer stars to confuse you but increasing the possibility that you might miss the alignment star altogether.
Missing the alignment star was something that happened repeatedly the first time I, the two astronomers and a film documentarian tried to use the telescopes. But familiarity quickly bred accuracy.
It should be noted here that both Meade and Celestron produce telescopes that eliminate these delays with controllers that not only find stars and focus on them but also include global positioning systems (at much greater expense) so that the telescope knows its location at all times.
The LX-90, with its dark blue and black casing and no-nonsense exterior, looks like a miniature version of a telescope you might see in a major observatory.
Everything about it says that this is an instrument for a serious amateur astronomer.
In terms of design, however, the hand controller comes off as a third wheel. There is no holder for it on the telescope, meaning that it can just slip off and dangle with the slightest bump.
Combined with its sturdy metal tripod and full battery pack, the LX-90 weighs about 51pounds.
Purists will thump the telescope with a finger to see how quickly it will return to a vibration-free state. Parents have another standard: If my 2-year-old bumps into the telescope, will it fall over? The Meade shines here with its wide tripod footprint, solid two-arm base design that supports the scope and two handles for easy lifting.
By contrast, the Celestron NexStar8 is the Movado watch of telescopes. It's own hand controller fits neatly into the single, sweeping arm that supports the telescope, much like a car phone. It would look equally at home in an observatory or a museum of modern art. It's lighter than the Meade, and its mostly plastic tripod seems flimsy by comparison.
I set out on July 9 with just the Meade and a documentarian friend named Michael Bober who had been involved in filming the aftermath of the 1980 eruption of Mt. St. Helens. I figured that he would not be easily impressed. We set out for Mt. Wilson one night and arrived shortly after 11 p.m.
The first thing we learned was there is no such thing as idiot-proof astronomy or instant gratification. It didn't help that we somehow managed to tell the Autostar hand controller that we were in a Middle Eastern capital and not Southern California.
No matter how much we read and reread the instructions, we found it difficult to erase the original entry.
It took us nearly an hour to fix the problem and get the computer properly aligned and oriented.
Bober was at the eyepiece when he finally got a look at the moon hanging low in its waning gibbous phase.
"Wow" was the only word he could muster. I had been feeling bad about not arranging to take photographs through the LX-90, but no longer. Photos would not have done it justice. The moon seemed saucer-size, presented in almost three-dimensional relief. You could see not only small craters stand out but even the shadows inside them.
When the NexStar8 arrived, I took it and the Meade out for an evening on the roof of the UCLA astronomy department with the husband-and-wife astronomy team of Matt Malkin and Shoko Sakai. Here, unfortunately, we battled a gathering marine layer and a sharp temperature drop that gradually dimmed the mirrors with condensation.
On that night, I easily found Mars on both scopes before they did. On the Meade's stronger eyepiece, I could see a hint of the polar ice cap on Mars. Star clusters looked like milky splotches because of the conditions.
"It surprised me that you could get that much power and sophistication for that kind of money. I was actually quite impressed," Malkin said. "I was comparing [the Meade] to a pretty fancy scope we have mounted here for teaching purposes. I don't think that scope was better, which is remarkable."
For Sakai, it was clearly a night of slumming; the smallest telescopes she usually works on are at least 1 meter in size. "They were great for such small telescopes," she said. "I was very impressed. They are wonderful toys."
Later on, as my familiarity increased, star clusters no longer showed up as milky splotches but as individually bright pinpoints of light, particularly on the Meade, with its superior eyepiece. I only wish that Celestron had provided an eyepiece of similar power for a better side-by-side comparison.
Bottom line: I go to the gym often enough to be able to lug the Meade to various viewing sites around Southern California, particularly because it is sturdy enough to allow you to connect a camera for astrophotography. It's a real piece of work.
Ronald D. White covers workplace issues. He can be reached at email@example.com.
For information about reprinting this article, go to http://www.lats.com/rights/register.htm