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NexStar 11

Posted by Ed Moreno   08/09/2004 07:00AM

Review of the The Celestron NexStar 11
By: Ed Moreno ([email protected])

It has been a few years since I wrote my first review of the NexStar 11”, and now may be time to re-visit this scope from a review perspective. How has my ownership experience been? Would I do it again?

First, I would say that I am a telescope junky. I currently have 6 telescopes, and enjoy them all. Most come and go, not because I don’t like them, but because I enjoy trying different types. Over the years, the ability to try different telescopes has greatly refined my understanding of optics, telescope testing, and the pros and cons of the different designs available.

Through all of this, there is one telescope that has never left my possession, and frankly, has been THE telescope that all others have ultimately have had to compare to. While this might seem totally unfair to some, in fact, I consider it to be quite fair because in life, we constantly compare apples to oranges. Think about it… When people shop for a new vehicle, they might have to debate the merits of a mini-van compared to an SUV, or between a 40” Plasma TV and a 60” rear projection TV. So, to me, I DO believe that in the end, comparing totally different telescope types is totally fair. People compare apples to oranges every day.

So, if you are kind enough to keep this in mind while reading this, I would appreciate it.

The NexStar 11 has been, without a single doubt, the very best all-around telescope I have ever owned. Mine has optics that are quite good, and mechanicals that are near excellent. Mirror shift keeps me from saying truly excellent, but in every other way, the mechanical execution is excellent, with large roller bearings, metal gears, and strong forks, all nicely finished).

Here are some of my observing experiences:

Double-star:

Wider pairs are simply trivial. The double-double is a LARGE split. I routinely seek low separation doubles. .8” or .6” Doubles are the only ones that challenge me anymore, because the others are so simple. Again, seeing plays a part. Last night, I split a 6.4 – 8.3, .6 arc-second double that has eluded me the few times I tried for it before because of seeing. The faint companion actually sits ON the first diffraction ring of the primary, so conditions have to be well above average to make this split. It was a Raleigh split, and even though the stars were of considerably different magnitude, I was able to discern the secondary with some effort. Admittedly, this is a rare feat, but still shows what this kind of instrument is capable of. Still, here is an area that I do enjoy my large 6” refractor because on brighter pairs, it takes really exceptional seeing for the 11” to provide the esthetically pleasing splits that the refractors are capable of (though the 11” will usually still split many doubles of this type, just not with the lovely airy patterns visible). Also my 152ED refractor shows subtle color exceptionally well, and here, all of the big refractors I have owned have been unbeatable by anything I have looked through.

Clusters:

Per inch of aperture, dobs do it better, but then again, in my light polluted sky, FINDING some of the fainter objects becomes a problem unless you can use digital circles on the Dob. The electronic drive makes it possible for me to locate clusters just at the bare limit of perceptibility all the time. Consequently, even on nights with bright moons, I can still locate a great number of objects even when I can’t see much more than the brightest guide stars in the sky!!! I know people that won’t observe in a full moon sky. I can see plenty in a full moon sky. Still, some of the newer dobs from at least on manufacture come with encoders at such an outrageously low price that I perceive that a 10” dob will make a more compelling argument for deep sky work than the $3000 cost of the NexStar 11. Of course regular dobs offer a wider field of view, and some will argue that this makes it easier to find objects, but here is my experience: When I use lower power in a large scope, the sky background starts to further wash out the ability to detect the faint objects. I have had many occasions where a super-faint cluster would not be detectable in my 35mm Panoptic, but would start to show up in a 15mm Plossl because of the magnification effect of darkening the background. If I am careful with my alignment, the Nexstar will put most targets in the field of view of a 15mm Plossl. But for wide clusters, the dobs will be the best choice.

Nebulas: See above….

Planetary performance: Well, You can do a little better on Jupiter, but it is going to either cost you a BUNDLE of money to use a large refractor and the requisite mount, or you will require a specialized Newtonian that will track (if that is important to you, and it is VERY important to me), or a big dob that will have to be pushed, or placed on a tracking platform. For high-power planetary performance, the N11 has beat everything I have put against it that costs less, and a few that I have put against it that cost the same or even more when you include the mount, which is fair considering the N11 comes with its mount. Seeing is a factor, and in fact it is a BIG factor. But when seeing cooperates, the N11 can present exceptional detail. When it doesn’t, to me, it doesn’t matter WHAT you are looking through, you are not going to see a GREAT view. Some might argue that a high quality refractor will show a more pleasing image on such nights, but the fact that the image is still degraded means that you are failing to use such an expensive instrument to its best advantage, so it becomes less of a value under this condition. Still, I have recently decided to build a specialized Newtonian to try to get improved views of the Jupiter. It is the ONLY solar system target that I think could be improved on with a specialized newt. Saturn is sublime in the N11. I consider Saturn to be a fairly high-contrast object, so the 11” aperture does quite well here. Mars was fantastic last year. While contrast available to me in my N11 is probably close to that offered by a 6” refractor, on Mars RESOLUTION plays a bigger factor. Many of the features on Mars are relatively high contrast, so I don’t think that contrast is as essential as on Jupiter. At the impromptu “Mars Party” that occurred at a local observing spot last year, I looked through every refractor present up to 6” of aperture, and the few large dobs present (largest was a 14”), and on this one night, I felt that the N11 bested them all, though the 14” was not well collimated when I looked though it. Also, I was unable to steer well-enough to use the power available in the biggest dob, but that was my fault, not the dob’s.

Lunar:

Nothing I have owned smaller has been better. Every time I look at the moon through the N11, I discover more than the last time. The resolution that an 11” aperture gives you is in such a totally different class than a 6” to 8” aperture that you have to see it to appreciate it. And at the powers I am sometimes capable of using (infrequently at best, but it does happen), tracking becomes essential. Teasing out super-fine detail requires that the object stay still in the eyepiece. Multiple craters in Plato, detail in the Alpine Valley, the spider-like complex of rills around Treisnecker???? Except for the lunar orbiter satellite pictures, I have not seen many earth-based pictures that show more detail than I can see at the eyepiece of the N11 on these targets. Lunar Atlas’s fail to name MOST of the details I see when I look at the moon. The N11 has provided the best lunar observing I have ever done. See comments regarding seeing above though. Seeing this kind of detail requires great seeing and a very steady mount.

Ergonomics and ease of use:

Best observing position of any telescope I have ever owned. I purchased an observing chair early this year, and at the most, I have to move the seat up and down maybe 18” to reach the eyepiece for any orientation of the OTA. I can stay seated under a blanket during the winter with a heater under me and stay toasty, and still roam around a big chunk of sky without moving my chair. My refractors, by comparison, make me lower the chair to the point that I am practically squatting on the ground, even on my very high CI700 mount.

The design of the OTA/Fork makes it easier to move than one would believe, however I find it to be at the top of my 6’, 190 pound (wink) frame’s REASONABLE limit. It isn't the weight as much as it is the bulk.

From first touching the scope to having it mounted and ready for alignment takes me 6 minutes. SIX minutes. My drill... I keep the OTA/FA set-up inside and attached to the base with one screw. Loosen and remove screw, put it in the Lazy-Susan on the tripod base. Lift OTA/FA and set on short dresser nearby. Lift fully assembled tripod with anti-vibration pads, crab it though the door, and throw on patio. I don’t level. I Don’t need to... Pointing and tracking is still fine with careful star alignment. I Return to house and pick up OTA, carry out, and drop. I have gotten so good at this that I hit the pin-guide every time. Bolt in the three bolts (which I can do in the dark by feel) and I am set up. A trip inside and power-on happens a few seconds later. While GPS aquisition is taking place, I go for eyepieces and star charts.

My ONLY complaints are these:

Dew…. You HAVE to have a strategy to deal with it... I use a commercial dew heater). Software… Overall, great except that I would like ADS cross reference or Strove catalog down to mag 10 seconary stars, AND I would like more than ANYTHING ELSE in the WORLD (Santa, are you listening?) access to deep sky objects by CONSTELLATION! Liberate me from my charts!!! Ok. Whew. That is off of my chest.

So, when the dust as settled, of all the telescopes I have ever owned, and may be likely to own, this one is THE keeper. SCTs get a bad rap from many, but for this observer, I find them to offer such a compelling all-around package as to be far greater in utility and use than the few optical compromises this design requires would suggest. Don’t let anyone fool you and tell you that a mid-size SCT is a bad compromise. In fact, it is perhaps the BEST compromise, because in astronomy equipment, everything is a compromise of one kind or another. Here, you give up a little absolute performance that a perfect 11” aperture reflector COULD give you but in the end you get SOOO much in terms of ease and comfort of use, and FULLY utilized observing time! It MIGHT get better than this, but after 25 telescopes (and I have enjoyed almost all of them), I am beginning to wonder if this isn’t the GT40 LeMans racer of the telescope world – a compromise built to win… It has surely won me over.

My regards,
Ed

Click here for info about the Celestron NexStar 11 with GPS
. -Ed.