Which Goto?

[Airconvent]

Well, there has been some talk about the "best" goto mechanism.
Mainly there are 4 available :

1. Meade Autostar
2. Celestron Computer Controller
3. Sphinx
4. Sky Sensor

I don't have the 3rd and 4th one, so can't comment much except to say both are equatorial-based and the sphinx has a cool graphical interface.

Autostar
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What I like about about the autostar is the features it had on top of the basic goto.
a. There is a simple sync mode to improve tracking after alignment.
b. A spiral search function to look for an object outside the ep field of view.
c. An automated backlash function that measures and sets the correct value for you.
d. A flashable ROM and lots of upgrade from Meade
e. One star alignment for instances where you do not have alot of stars to align to.
f. Built-in LED torchlight.
g. Power saving mode but keeping the scope tracking.
h. LED display brightness/contrast function .
i. Battery indicator function.
j. Easy search by object type function (globulars, nebulae, etc)
k. Custom tours that can be created on the pc. there are alot already existing for the autostar, especially from Dr Clay Sherrod.
l. Ability to go to an object/star and it will tell you what that object is.
m. Timezone automatically set once you input your country.


Celestron Controller
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1. I only have the older N8 which features basic functions, so its not fair to compare. Can those with the latest sky align version please continue from here? otherwise this controller does not have most of the features found on the autostar above.
2. What is cool about the Nexstar controller is its easier to setup. If you don't need to see planets, you don't need to key in the time.

Can those who own the Sphinx and Sky Sensor also elaborate on what is good/bad about their gotos?

rich

[perseid]

Er...what about sky-watchers HEQ5 goto?
I have it in stock but have yet to test it out yet. Maybe you can view it from your local sky-watcher dealer.
I like sphinx but it is a bit pricey. I only have experience in the GOTO in Nexstar 130GT. The goto is very accurate. If you do alignment properly, the scope could put the desire objects in the center of a 25mm eyepiece. The only thing I don't like about it, is that the scope cannot be pointed directly overhead as the tube would hit the mount!

[Airconvent]

Er...what about sky-watchers HEQ5 goto?
I have it in stock but have yet to test it out yet. Maybe you can view it from your local sky-watcher dealer.
I like sphinx but it is a bit pricey. I only have experience in the GOTO in Nexstar 130GT. The goto is very accurate. If you do alignment properly, the scope could put the desire objects in the center of a 25mm eyepiece. The only thing I don't like about it, is that the scope cannot be pointed directly overhead as the tube would hit the mount!

hi ck..no...don't know about the skywatcher one but I suspect they are merely oem versions of the Celestron one. Much like the old Tasco gotos.
If you chose a fork mounted goto, then you don't have to worry about not having a pier..heh heh

[weixing]

Hi,
If you read my previous observation report, you'll know which GOTO I'll vote for :
1. SkySensor 2000
2. Celestron GOTO
3. AutoStar GOTO

Other than the SkySensor 2000, I only used NexStar (Jacky CG5-GT), AutoStar (Daniel LX-90) and Sphinx a few times. Generally, I found out that NexStar GOTO is slightly more accurate than AutoStar, but alignment in NexStar is more difficult than the AutoStar. I think the reason is that NexStar use 3 star alignment instead of 2 star alignment in AutoStar (does AutoStar have a 3 star alignment??).

About Sphinx, I only use one or two times, so can't comment much.

About SkySensor 2000, I have used for a few observation session... from alignment to GOTO. I'm really impressed by it... I would said if I'm going to get a GOTO, SkySensor 2000 is my only choice at the moment. The below is something that I think other GOTOs are missing:
1. Do not require polar alignment for visual use (for EQ mount GOTO).
2. Do not enforce alignment (of course your GOTO will be out if you don't do alignment).
3. Can basically use any objects in it database as an alignment objects,
4. The SkySensor 2000 will automatically select the best 3-point alignment for you if you align more than 3 objects.
5. Power fail safe. Don't need to do alignment again after power fail. See below.
6. Do not require to do alignment even you switch off the power or change battery as long as you don't touch your mount.
7. Can GOTO 130++ features on the Moon.
8. Can use it to assist you to do drift star alignment.
9. Can move the scope in different mode... RA/DEC, Alt-Az and X-Y.
10. Can go manual mode if manual clutch is installed (must be careful when doing GOTO if manual clutch is installed. Both manual clutch may hit each other in certain odd position). Useful if you run out of power and still want to observe.

Have a nice day.

PS: SkySensor 2000 virus attack again. =P =P =P

[ariefm71]

I concur with wxg, compared to my previous celestron goto, the ss2k is way more accurate, more silent, easier, and has much more features. Don't be surprised if I'm getting another one in the future :-)

[starfinder]

The below is something that I think other GOTOs are missing:
2. Do not enforce alignment (of course your GOTO will be out if you don't do alignment).

Hi,

I have the Meade LX-90 (Autostar). Been using it for a few years in Alt-azimuth mode.


Regarding alignment, I disagree with some points.

(1) If you don't want to, you don't need to do any alignment for casual observing.

For example, when I usually do planetary viewing from my window, I just level the OTA and point it to North. It is then in the Home position and is already roughly aligned. Then when I turn on the power, after entering the date and time, I skip alignment and press the keys to Goto e.g. Jupiter. The scope then brings Jupiter to within the field of view of the 8x50 finder. When I center Jupiter in the eyepiece, I just press "Enter to Sync" and it tracks very well after that.

I find this method so convenient.


(2) If the scope is already aligned, you can "Park" it and switch off Autostar with the alignment saved. As long as the scope and OTA are not moved, the alignment will still be there. Just re-enter date and time after switching it on.



Further comments,

(3) I have found Autostar on the LX-90 to be very accurate. A few years ago, I did a Messier Marathon at Mersing over 2 nights in around April. The LX-90 danced through the sky precisely and I got over 80 or 90 objects, including many faint galaxies. With my level of experience, it would not have been possible without the Goto.


(4) The tracking on the LX-90 Autostar is superb. I'm constantly amazed at how well it can track an object. I know how fast an object moves at 300x if one is not using a motorised equatorial mount or a scope with tracking. With the Autostar, I can leave an object in the field of view of a high power eyepiece (e.g. 300x), come back an hour later, and it's still there.


(5) If you want to do alignment, the Autostar system is very logical and is easy. You can do Auto-alignment whereby the scope chooses 2 stars above the horizon at that point in time. The choice of stars is very good. (Or, you can do a manual 1 or 2 star align whereby you choose your own stars.) I had a brief experience with Nexstar once, and I found the choice of stars not as good.


(6) There is no backlash at all. The movement is very smooth even at extremely slow speeds.


The above relates to my experiences of Autostar with the LX-90 in the normal Alt-azimuth mode. It may differ with other Meade scopes because the mechanics might be different.


I agree that it would be better if Autostar remembers the alignment if the power went off suddenly, e.g. where the power cord comes off accidently.


(( Also, there *was" one Goto system whereby you could move the OTA manually after doing the alignment, and the scope will still be in alignment. That was the Celstron Ultima 2000 8" SCT. The Meade dealer in Sydney whom I spoke with last month told me that the Ultima 2000 could do that because the encoders were placed in the gears or something, unlike all other designs. ))


It would also be good if Autostar had a feature whereby you can call up all the deep sky objects within a constellation. As it is, you can only call up all the bright stars within a constellation.

However, it has the entire Messier, Caldwell, NGC and I think IC database, so finding DSOs is easy. Further, you can just enter the RA/Dec co-ordinates of any object and go to that. And it has databases of types of objects, e.g. Planetaries, Galaxies, Open Clusters, etc.

[weixing]

Hi,

(1) If you don't want to, you don't need to do any alignment for casual observing.

For example, when I usually do planetary viewing from my window, I just level the OTA and point it to North. It is then in the Home position and is already roughly aligned. Then when I turn on the power, after entering the date and time, I skip alignment and press the keys to Goto e.g. Jupiter. The scope then brings Jupiter to within the field of view of the 8x50 finder. When I center Jupiter in the eyepiece, I just press "Enter to Sync" and it tracks very well after that.

I find this method so convenient.

Do you need to point to north accurately?? Also, if we decided to do alignment after doing what you mention, do we need to move the scope to the initial position and switch the power off and on again to do the alignment??

(5) If you want to do alignment, the Autostar system is very logical and is easy. You can do Auto-alignment whereby the scope chooses 2 stars above the horizon at that point in time. The choice of stars is very good. (Or, you can do a manual 1 or 2 star align whereby you choose your own stars.) I had a brief experience with Nexstar once, and I found the choice of stars not as good.

I found a lots of the star's name given by the AutoStar (same with NexStar) is very uncommon... always have a hard time trying to figure out which star is that on the Star Chart... (I'm not an expert on star's name =P ) Do you have a list of all the alignment stars given in AutoStar, so that next time won't be having a hard time wondering which star is that...

(( Also, there *was" one Goto system whereby you could move the OTA manually after doing the alignment, and the scope will still be in alignment. That was the Celstron Ultima 2000 8" SCT. The Meade dealer in Sydney whom I spoke with last month told me that the Ultima 2000 could do that because the encoders were placed in the gears or something, unlike all other designs. ))

I think the only way to do this is to put the encoder on the axis itself and design a clutch like mechanism to disengage the motor when you move the scope manually. Most GOTO encoder is in the motor itself or on the gear and don't have a clutch mechanisms, so can't do that. Hmm.. Since Losmandy EQ mount allow to move the scope manually without disenage the motor, I wonder can Losmandy GEMINI GOTO do that??

Anyway, I found on some website that when you connect the external encoder to the SkySensor 2000, it became a DSC. Hmm... that'll be interesting...

Have a nice day.

[ariefm71]

Anyway, I found on some website that when you connect the external encoder to the SkySensor 2000, it became a DSC. Hmm... that'll be interesting...

Yes, there's encoder port on SS2K that will make it a DSC (damn good one i must say).

[ivanong]

Hi, I had a GP-DX, then a Sphinx, now currently a EM-200. The Sphinx works very nice for visual GOTO and for webcamming of planets. There is a marginal gain in stability in the mount over the GP-DX, and the Sphinx tripod is an improvement over the GP HAL tripod. I used a Tak 4" and C9.25" on the Sphinx. The 4" worked well but the 9.25" was a little over the top, although the Sphinx handled it much better than my GP-DX.

What was dissappointing with the Sphinx was that the DEC backlash was very bad, even after the software upgrade with the backlash compensation feature. My STV would not even calibrate it and I had to manually increase calibration time to 30 sec, and it was touch and go at best. Manual guiding was even more frustrating- I am sure the bears and night creatures up in the mountains have heard me yell out a few times. That was the reason I sold the Sphinx. The EM-200 is a dream! No problems whatsoever.

I like the Sphinx becuase you do not have to be accurately polar aligned in order for it to track properly or for the GOTO to work. For example, if you are looking at the sun, you just center it, align on that, and it will track decently even if you are a couple of degress off. Of course for photography, a good polar alingment helps. The polar scope is expensive but is very accurate. Having said all that, I still think the Sky Sensor has more functional features, unless you like that cute monitor on the Sphinx.
The monitor gets very sluggish below 0C but in Singapore you will not have that issue

Cheers-Ivan

[Jin Peng]

Republic Poly Astro Club has got one GOTO....the sphinx mount, well, looking for speed, choose the sphinx man! 1200x sideral speed, how to resist!