Celestron NexStar 80 GT

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Celestron NexStar 80 GT
Recognizing this scope for what it is in it's price range, it's an exceptional deal!! It's a decent telescope with decent optics. It is INCREDIBLY PORTABLE!! And I don't even need to bring star charts! I have been out more frequently with this scope than others, and expect that I will use it much more frequently throughout 2001. I had been resistant to the idea of "go to" technology, as part of what I enjoy about backyard astronomy is the "hunt" for deep sky objects. The thing is, with this scope, I can either hunt, using the directional controls and a start chart, or use the go-to feature, which offers the opportunity of seeing more in a shorter period of time -- and sometimes, I just want to do casual observing, rather than hunting (and sitting at the eyepiece for 20 minutes, waiting for my eye to catch an extra whisp of detail.) The go to feature works -- it doesn't hurt that this is a wide field scope either. It is slow, but I'm slower. One thing: the instructions tell you that when you turn on your and controller for the first time, you'll be asked to select what kind of scope you have -- but in practice, this won't happen. The reason why is they already did preset it in "Custom Mode" with special values to make the goto feature work right. The problem is, you can scroll thru and change the type of scope from their factory custom setting to 80mm or whatever type of scope you happen to have, and when you do, you'll lose important data, and the goto feature won't work until you call tech support and receive instructions on how to re-enter the appropriate values that need to be entered in the custom setting. So just leave it in the custom setting. This problem cost me a couple of good observing nights, and I even returned the computerized drive of I originally got, for another. I won't knock off points for the confusion caused by the instructions, though -- I give it a 9, that is a 9 taking into account that this is a 400 dollar scope.

Overall Rating: 9
Weight: 3 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40826

Celestron NexStar 80 GT
I bought this as a first telescope, because of the portability, and the GOTO facility, which should, I repeat should have made for instant gratification for my little boys 6 and 7 years.It is very quick to set up. Optically much is said elsewhere on this site about this tube assembly, so I reiterate most of that here, except to add that for me, a beginner, views seem very bright, almost too bright on things like Jupiter, and I feel if I could just turn down the brightness I would see more. It accepts 125x with a 3.2mm Plossl easily, but there is no depth of field of course. The optical coatings are there, but not as dark as say my Minolta camera lenses.I like the star pointer instead of a cheap plastic 6x30 spotting scope, but it must be adjusted alt-az exactly or centering during auto-alignment with the GOTO is inaccurate,also if aligning on an object near the zenith it can be a pain.Soooo for the optical part 8-9 out of 10.
Now the bad part, the GOTO. OK I live in the Uk almost on 0 degrees (3 degrees 5 mins west actually). During the setup procedure, you have to tell the computer if your time zone is daylight saving or not. I dont know whether I need to make this adjustment or not, being firmly in GMT, and the manual doesn't say.I await Celestrons response. Obviously this crucial step will either aid alignment or make an error of 15 degrees. In reality I have found the acuracy so difficult to estimate either way, that I cant tell which one is right.
I have never been able to spot a target exactly, at medium powers, I always have to centre the object in the field, I dont know whether this screws the auto alignment out or not.
I am not getting any tracking time at all, I continually have to recenter, at 125X the time I have before the image drifts out of field is very short, certainly less than 1 minute ( I know the field is very narrow at this power of lens), the lower the powered eyepiece of course the longer the object is in the field. I certainly could not track for long exposures with a camera with this.
The Hand set has a life of its own and sometimes goes off completely.
The battery pack is cheap and nasty and whether placed on the tripod shelf, or in a pocket to aid battery efficiency, twice the cord has wrapped round the tripod and pulled out the plug, losing power and resulting in aligning again.

You will gather i'm pretty unimpressed with the GOTO, I await Celestrons response, and that of my dealer after the holidays, but all in all it looks like this lot is going back. zero points for the GOTO.

Overall Rating: 8
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40828

Celestron NexStar 80 GT
looking at my review above as a whole this scope should have had a 2-3 overall.

Overall Rating: No Vote
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Celestron NexStar 80 GT
I have only been able to have my scope out 3 or 4 times in the three months that I have had it. Those times were looking through sucker holes or dealing with high alt. clouds and low alt. clouds (fog). I am impressed with what I saw. I have not yet tested it on stars. Waiting for a clear stable sky before I make a judgement on that. However others in other forums have much good to say about the OTA.

Now for the mount. I cannot get over how such a flimsy looking tripod can be so stable. I don't even put in the acc. tray and it is still much more stable than my C8. The GOTO is kind of tricky. The most important factor in getting and maintaining a good alignment is not really the optical part but the power supply. You must have fresh batteries! Better, is to get a cigarette lighter adapter cord. When the batteries go down with just a few (3-4) hours of use, the computer will loose the alignment when slewing at high speeds and then reversing as it sometimes will do. The current demands of the motors causes the battery voltage to drop momentarily below what it takes to maitain alignment. This will not happen if you run of a car battery. Also you have to watch the power cord and the plug. If the plug gets jostled too much, there is another cause of computer alignment loss. When things go right, as they did the first time I got it aligned, the first night out, everything I looked at was in the FOV of the 25mm ep and most things were in the FOV of the 10mm or so close that you can defocus until you see the light and follow the light while you refocus.
If I like it so much, why did I not rate it a 10? First, it's hard to rate anything a 10, but that is not the reason. You will find on the outside of the box and several places on the net and on the Celestron site and in the manual the mention of several facilities that in fact do not work at this time. The one that bugs me it that the connector on the hand controller to allow your computer to control the scope is not operational and Celestron says they are going to fix it. They do not say when or if the fix will be a free retrofit.

There you have my $0.02
George

Overall Rating: 9
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40831

Celestron NexStar 80 GT
Optically, this scope is a winner. Check out the 80f5 group in egroups.com. You need to get a couple of better eyepieces and if nothing else get a good replacement for the diagonal preferably a mirror type, and use the Celestron one for an ash tray. The Cassinni division is easy in a downtown Portland, OR backyard.

Overall Rating: No Vote
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Celestron NexStar 80 GT
This is a wonderful telescope for the beginner. I agree with most of the other comments offered here. Resolution and optics quality is very good, a far cry from department store scopes. The star finder is very good. The manual could use some fine tuning as per other comments, I had similar problems and needed to call customer service. They were very helpful, tho I suspect the factory coding entered in my telescope was for a different model. With new codes input the telescope worked nicely. The "go to" feature was not perfect, but not bad either. Some fine adjustment is usually needed, but its simple to use. Hidden in the manual, they recommend slewing from the up button and right button. This is good advice and should be more prominently displayed. I velcroed the battery pack to the arm(fork) which holds the tube assembly and solved the problem of the cord wrapping around the tripod etc. It was the biggest problem we had, until solved. The comment about short battery life is on target, also about the diagonal. With 2X barlow and 6.5 plossl (not included) this is a great entry level scope. Very portable and after a couple of times easy to align, the Go To feature is just what we needed to quickly find the planets and stars. Great rings of Saturn, Jupiter is breathtaking. Can be used for terrestrial viewing with another diagonal, not included. This telescope is not a "light bucket" but it is surprisingly bright for a small relatively inexpensive model. Get a moon filter. Nice optics, easy to move and operate after a night or two of practice, this is just the telescope for a casual viewer looking for great images of the planets and stars. Without the "go to" feature it would have taken me days to find the local star charts and then locate everything we saw on our first night of use. I would buy this telescope again.

Overall Rating: 9
Weight: 3 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40833

Celestron NexStar 80 GT
This scope performs very well if one recognises the limitations of its 80mm apperture and its short f5 focal ratio. I specifically bought this scope to fill a gap - namely something that would be easy to set up and was portable enough that I could take with me on vacation etc. There are some minor problems with the computerised element - mainly to do with the inaccuracy of the manual than anything else. However, I've been impressed with how well it performs. It's very quick to set up, taking no more than 10/15 minutes including auto-aligning. The accuracy of the GOTO feature is reasonably good, usually putting objects within the field of view if auto-aligning correctly set up. Visually, I've been pleasantly surprised. Although it is better suited to viewing stars and deep-sky objects, both Jupiter and Saturn have shown up very well - the other night I was able to see quite a lot of detail on Jupiter's surface, including IO transit, and the Cassini division was clearly visible on Saturn. Although there is noticeable chromatic abberation with such bright objects, I didn't think that it distracted too much from the views - better eyepieces than the supplied SMA's will no doubt improve things no end.

To conclude, given the apperture/focal ratio limitations of this scope, I was more than impressed with its abilities on even bright objects like the moon and planets. There are some glitches with the computerised element but nothing to write home about. I would recommend this scope for someone who wants portability with ease of set up - perhaps as a back-up for travelling purposes.

Mike Kelly, Leeds, UK
mjkelly62@hotmail.com

Overall Rating: 9
Weight: 3 (Unreliable Vote)
Date:
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40834

Celestron NexStar 80 GT
I picked out the GT 80 as the scope to allow me to "re-enter" astronomy after being out of it for 30 years. The scope far exceeds my expectations, and the more I use it the more I like it Here's why:
- Excellent value for the $.
- GOTO is EASY to use, and lets me spend more time looking AT than looking FOR objects.
- Very easy to transport and set up. I carry mine in a padded backpack/camera case! When I fly, it's carry on luggage.

Here are some lessons:
- If you are new to astronomy, you'll need to learn the names & locations of some bright "guide stars" to set you scope up. Get a star chart for this - it's part of the fun.
- I found that the scope is better for star clusters than planets, a function of it's relatively low power. (Not to worry - there are far more star clusters than planets!)
- I recommend purchasing a Barlow lens (Celestron Ultima) to boost the power of the scope a bit.
- Also recommend purschasing a NexStar 17mm Plossol. This is a GREAT match for this scope!
- Have fun!!!!

pat_agnew@fpl.com

Overall Rating: No Vote
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40835

Celestron NexStar 80 GT
These scopes are made in China and have poor Q-C. While the design and optics are OK the manufacturing and quality control is poor at best. These scopes do not have all of the features that Celestron claims such as a monthly tour of objects or two star alignment or a functional Pc interface. Celestron is owned by Tasco which says allot.
The first 80 GT I got in Dec 2000 was extreamly erattic. I spent more time re-aligning it than I did looking a objects. I returned it for a second unit. That one got pretty beat up in shipping due to the bad design of the factory packaging. I sent it to celestron service in CA. They sent it back saying it was ok. I took it apart and found a couple of obviously dammaged parts. I called customer service and told them. They said send it down again and they would replace the dammaged parts. I did and they sent it back to me with a reprimand for looking into it myself and directed me to the instructions for setting the backlash comp. I admit that Im an idiot and I don't know how I've mannage to service electro-mechanical devices in the audio industry for the last twenty five years. But the Celestron service boys are so sharp they did not even disassyemble the mount to check out my complaints or attempt to fix it. The unit was still very sloppy and unstable. I exchanged that one for a NexStar114 hoping that I can tinker with the mount and electronics and make it functional enough for a 102mm refractor. I geuss i am a fool!!!! I should have exchanged it for the 90mm refractor on the EQ mount and not spent the extra $100 but I was determined to go-to....
These are not stable or precision pointing devices!!!! The battery AA pack is useless as the little scopes really suck up the juice. Get a 5 or 6 Ah lead acid battery If you want to use the scope for more than a couple of hours.
If you have dreams of the scope smoothly gliding from objoct to object with computer precision, forget it! You will spend most of your time aligning and re-alinging and powering up and down as the unit locks up or goes in to a spinning nose dive.
Unless you like to futz with electro-mechanical do-dads you will get allot more for your money with a good EQ mount and a Star Chart.

Overall Rating: 1
Weight: 6 (Veritable Vote)
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Celestron NexStar 80 GT
the best telescope I have ever used

Overall Rating: 10
Weight: 1 (Unreliable Vote)
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Celestron NexStar 80 GT
Very bright but very bad for color correction - due mainly to the short focal lentgh. Not good for looking at much due to the extremly short focal lentgh. Getting to 150X requires a 3mm lens - thats small!!! Still, for getting a basic view of stuff it is very good. Just wish the focal lentgh was 600-800mm. Then it would be more useful. Pluses - the goto capabilities are very good for such an inexpensive scope.

Overall Rating: 6
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40839

Celestron NexStar 80 GT
PAID $350 FOR MY NEXSTAR80MM SHARP VIEWS AT 80X AFTER THAT OUT COMES THE RAINBOW AND PURPLE COLORS RETURNED IT GOT CASH BACK I THEN ORDERED A ASTELE/LOMO
60MM MAKSUTOV CASSEGRAIN AT OPTICSPLANET FOR $130 FREE SHIPPING THIS TELESCOPE IS HALF THE SIZE OF THE NEXSTAR 80MM IT FITS IN A LARGE COAT POCKET ITS ALL METALCONSTRUCTION ITS QUALITY IS AS GOOD AS A $700 70MM APO THE IMAGE QUALITY OF THIS LITTLE SCOPE IS RAZOR SHARP UP TO 200X WITH NO IMAGE BREAK DOWN AND NO COLOR THE FOCUSER IS BUTTER SMOOTH THIS TELESCOPE IS A WORK OF ART COMES WITH A GREAT 25MM EYEPIECE.WILL BUY SOME MORE EYEPIECES AND A GOOD BARLOW WITH THE REST OF MY MONEY.

Overall Rating: 4
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40840

Celestron NexStar 80 GT
THE OTA:

The optical quality of the air-spaced 80 mm doublet is on a par with the typical short tube refractors available from several companies. Remember these are not high-end refractors. You're getting a binocular lens designed to work best at 20X, not 240X, and they're intended for wide field, low-power views. Don't expect much at magnifications higher than 40X (the max with the supplied 10 mm eyepiece), and you won't be disappointed.

The mechanics of the OTA are typical Chinese plastic and pot-metal. The lens cell is entirely plastic, but the rack & pinion focuser is in a cast-metal rear cell assembly. The inside of the OTA is blackened, with one baffle ring located about halfway down the tube. The focuser was smooth, but the clamp that holds the diagonal was weak, and it could use another set screw for better security.

The rear cell also has a dovetail slot for the included red-dot finder. This is a nice accessory, but I found it wasn't really needed because this scope has such a wide field of view. The OTA attaches to the mount very easily with a single thumbscrew and clamp, and it can be rotated to position the focus knobs.

NEXSTAR GOTO MOUNT:

I bought this scope to get a look at the NexStar mount. I was curious to see how well Celestron managed to fit a two-axis servo and goto in such a small and elegant design. Considering the price, I think they did a good job, but there are compromises that serious observers should note.

The tripod is all-aluminum, and not suited for high magnifications because it's too shaky. This isn't a big deal at 40X, but Celestron uses this same tripod for other scopes, so buyer beware on this one. A plastic, "deluxe" (?) accessory tray is included with the tripod and comes in handy for holding eyepices. The separate goto assembly attaches to the tripod easily with one captive mounting screw.

The goto mount assembly is a combination of cast-metal and plastic parts. The load-bearing arm is metal, but all of the other parts are plastic. A separate battery pack holds eight AA-size cells, and attaches to the mount with an extension cord and plug. This battery pack drains very quickly, so take the advice others have given, and buy a portable 12V power pack to run the scope.

The Nexstar hand controller is all plastic with a 2-line LCD display and white, rubbery buttons. It attaches to the mount with a coiled cord and the typical RJ-11 phone jack. A plastic bracket is supplied to hang the controller on one of the tripod legs. I was happy to find that the hand controller has red backlighting for the display and buttons making it easy to read while observing.


HOW WELL DOES IT WORK?

Celestron's marketing department seems to have exagerrated the features of this version of the Nexstar system. The most important procedure for any goto system is the initial alignment because this tells the computer where you are, and allows it to generate the coordinates for finding other objects. With this controller, _only_ the auto-align mode can be used. This means that only the computer can select the objects used for aligninment. Celestron's manual is unclear about this, and seems to imply that the user can select objects for alignment, but apparently this is only true for the more expensive and elaborate Nexstar controllers.

One problem with letting the computer pick the alignment stars is that sometimes they're behind a tree or building. Users can tell the controller to go to another star when this happens, but it goes through its list of available stars in alphabetical order, and this wastes a LOT of time. I found it very frustrating to repeatedly go through several levels of menus to set up the system. The manual is not clear about what information gets saved and survives a power-down, and the display does not show any previously entered values.

Goto accuracy is fine for placing objects in the FOV for a low power eyepiece, and for this scope it works well. The motors are (to me) noisy when slewing at high speed, and they make weird (again to me) sounds while tracking in alt-az mode. The controller has a menu for an equatorial tracking mode, but there is no way to use it with this tripod.

This set up is a reasonably good value (I paid $330), but I'm giving it a "6" rating because the various components aren't durable enough for long-term use, and because the controller limits selection of alignment stars. From previous experience, I know the plastic parts on the tripod won't survive cold weather observing sessions. The supplied battery pack is inadequate, and must be replaced as well.

Overall Rating: 6
Weight: 6 (Veritable Vote)
Date:
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=40841

Celestron NexStar 80 GT
I like this scope alot. I bought it to have a travel scope, and it is great for that. Also note that prevous comments about only haveing "auto" alignment are no longer true. The newer ones have an updated handset that also allows 2 star alignment. It can be a bit tricky to get it aligned correctlyk, but if you are patient, you will be rewarded with good goto ability and decent tracking at low to medium power.
Also note that instead of a moon filter, you can use the aperature stop that is built into the lense cap. The center of the lense cap comes out, stopping the aperture to maybe 40 mm. It helps a bit with brightness of the moon and Jupiter...along with reducing the chromatic abberation on bright objects as well. Of course, you would only want to use this on very bright objects, since it really does reduce the amout of light gathered.
I like mine...for $300, it has been a fun investment. Also note that the views are MUCH better using decent Plossl lenses, such as Meade 3000 rather than the SMA lenses that came with.

Overall Rating: 7
Optics:6 Mount:8 Ease of Use:5 Value:8
Weight: 1 (Unreliable Vote)
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=81035

Celestron NexStar 80 GT
Love this scope. Its size makes it easily portable for a small person. You don't have to break it down to store it -- leave it on the tripod in a spare room. The hand control is easy and does what it says it should do. The newer HC allows for easy alignment, much moreso than the older one (see Celestron if you think you have the old one and they'll upgrade you). With a little practice, you can see a lot even with some light pollution and as it happens, you can mount other tubes onto the mount and make an upgraded goto scope! So, there are possibilities other than just getting an entirely new scope when you're ready for a bit more aperture.

Overall Rating: 9
Optics:8 Mount:10 Ease of Use:9 Value:10
Weight: 1 (Unreliable Vote)
Date:
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=93942

Celestron NexStar 80 GT
Great little scope for a first scope owner. Nice wide views, easy to carry and to move around, gets a lot of use because of its small size.

Overall Rating: 9
Optics:8 Mount:9 Ease of Use:9 Value:10
Weight: 1 (Unreliable Vote)
Date:
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=118301

Celestron NexStar 80 GT
Over all seems like a pretty good scope for the money

Overall Rating: 6
Optics:7 Mount:8 Ease of Use:9 Value:6
Weight: 1 (Unreliable Vote)
Date:
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=156041

Celestron NexStar 80 GT
I've had one these little scopes for about three years now and overall I will have to second previous complaints about the package. The little battery pack that comes with the scope is inadaquate, The mount is very light (vibration suppression pads help) and the goto is somewhat erratic in operation. All that being said, it is an adequate wide field grab and go scope for wide field, low power observing. I buypass the goto 90% of the time and just use the drive for standard alt/az operation. The red dot finder is more than adaquate to locate objects. I would say this is a decent first scope or as a wide field scope for someone on a budget as long as you don,t expect to much of it. The image quality goes downhill fast above about 90X.

Overall Rating: 6
Optics:5 Mount:5 Ease of Use:7 Value:6
Weight: 1 (Unreliable Vote)
Date:
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=423995

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