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CG-5 Mount - Polar align, Go-To

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#1 deltav3

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Posted 11 February 2010 - 03:19 AM

I have a CG-5 Mount (HC version 4.16, MC 5.16) and have yet to get any Go-To accuracy after a polar align.

My steps:

1) 2 star
2) 1 star from list, than Polar align from 'Align' button
3) Unsync
4) Re-align the same 2 stars from the First align (polar align wrecks this so it is needed)
4) From list Menu choose another star, go into Calib stars and add the new star(s). (I add 1-4 does not seem to make much difference)

This puts M42 into the eyepiece, but any other objects ie: M81/82 I have nothing.

* Note I use a C8 with a 80mm refractor which does the imaging with a wider field of view (400mm F5) so Go-Tos do not need to be in the eyepiece.

Yet it can not even do that! Please let me know your procedure after a polar align to get Go-To Functioning.

Thanks

#2 HaleBopper

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Posted 11 February 2010 - 07:10 AM

Well unless you're doing AP, you don't really need to do a polar alignment. It's been a while since I did polar alignment on my CG5, but this is what I do and have not had any problems. Oh and I don't use the sync functions. I'm not not sure what you were "unsyncing".

1) Rough alignment on Polaris. Sometimes I eyeball it through the polar scope bore hole and put in the centre.

2) 2 star alignment

3) 1 or 2 calib stars. I find that it does not matter too much how many you use, but the more accurate, the closer to Polaris your mount will slew when doing Polar alignment.

4) Do the polar alignment and centre polaris WITHOUT using the HC.

5) Put the scope back to the index marks and go through the 2 star alignment again and add as many calibration stars as you can. I have an old version of the software so I can only add 3.

Hope this helps.

#3 rmollise

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Posted 11 February 2010 - 08:02 AM

I have a CG-5 Mount (HC version 4.16, MC 5.16) and have yet to get any Go-To accuracy after a polar align.

My steps:

1) 2 star
2) 1 star from list, than Polar align from 'Align' button
3) Unsync
4) Re-align the same 2 stars from the First align (polar align wrecks this so it is needed)
4) From list Menu choose another star, go into Calib stars and add the new star(s). (I add 1-4 does not seem to make much difference)

This puts M42 into the eyepiece, but any other objects ie: M81/82 I have nothing.

* Note I use a C8 with a 80mm refractor which does the imaging with a wider field of view (400mm F5) so Go-Tos do not need to be in the eyepiece.

Yet it can not even do that! Please let me know your procedure after a polar align to get Go-To Functioning.

Thanks


As you've been told polar alignment fwill have little or no effect on your go-to accuracy.

What you SHOULD worry about for obtaining best go-to accuracy:

1. Centering the correct stars. You can't be pretty sure, you must be SURE. Center using a medium power reticle eyepiece

2. Always use up and right for final centering.

3. Always run the mount with a fully charged 12vdc battery.

4. Add calibration stars until the next calibration star is at least in the finder center if not in the eyepiece when the slew stops.

When properly aligned, these mounts are extremely accurate go-to-wise.

#4 freestar8n

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Posted 11 February 2010 - 08:45 AM

Your step 4 statement that polar align wrecks goto should not be the case if things are working right. Even though the mount is moved, the PA routine compensates for it and should result in good GoTo after PA.

I would recommend doing a full calibration first so the mount is characterized and the GOTO ACCURACY is good - which does NOT require a good polar alignment - but IS necessary for the polar alignment to work well.

Then do the polar alignment routine carefully and immediately check to see if your GoTo is accurate enough. If it is, you are done; if not, realign on two stars but you shouldn't need calibration stars.

In short - I think your main problem is that in step 1 you only did a 2-star alignment and did not do a calibration.

Frank

#5 deltav3

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Posted 11 February 2010 - 10:49 AM

Thanks for the reply. But I would like to point out that the manual says that Go-To accuracy will be affected and is the case for me.

I have Dec,09 CG-5 (firmware already latest) so the supplied manual was reflecting an older firmware. The manual on celestron site even with revisions appears a bit off ("Addendum to the Advanced GT mount manual (firmware v.4.10). This leaves the process a bit random it seems.

In case you are wondering about the UnSync, after a polar align (All-Star) feature, this is required or you will be locked in a certain part of the sky. (polar align uses your final Finder/Center Eyepiece/Center
to sync on that part which needs to be undone)

anwsers to your questions:

My Go-To works fine, Why things do not work
after a polar align I do not know. So you at least Know My methods for a Normal Go-To work, and I get around 3 min unguided for a polar align at 400mm for imaging so my Polar align works. For power I use and Outlet not a battery.
I use a 25mm Eyepiece (yes,yes I know) I dont have all night to find stars, and you know its working because my my go-to accuracy(before polar) and polar align work (imaging time).

Just wondering do you have the same firmware version?



As you've been told polar alignment fwill have little or no effect on your go-to accuracy.

What you SHOULD worry about for obtaining best go-to accuracy:

1. Centering the correct stars. You can't be pretty sure, you must be SURE. Center using a medium power reticle eyepiece

2. Always use up and right for final centering.

3. Always run the mount with a fully charged 12vdc battery.

4. Add calibration stars until the next calibration star is at least in the finder center if not in the eyepiece when the slew stops.

When properly aligned, these mounts are extremely accurate go-to-wise.



#6 deltav3

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Posted 11 February 2010 - 11:01 AM

Do you mean Normal Go-To + 2-3 Calib stars than polar align? I gave this a try before same result. Oddly enough once I can actually find another Messier object than Add that as a calb Object it seems to goto the other objects no problem, very strange. (This is after a polar align + 2 calib stars)

I will give it another try tonight.

Thanks.

Your step 4 statement that polar align wrecks goto should not be the case if things are working right. Even though the mount is moved, the PA routine compensates for it and should result in good GoTo after PA.

I would recommend doing a full calibration first so the mount is characterized and the GOTO ACCURACY is good - which does NOT require a good polar alignment - but IS necessary for the polar alignment to work well.

Then do the polar alignment routine carefully and immediately check to see if your GoTo is accurate enough. If it is, you are done; if not, realign on two stars but you shouldn't need calibration stars.

In short - I think your main problem is that in step 1 you only did a 2-star alignment and did not do a calibration.

Frank



#7 rmollise

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Posted 11 February 2010 - 11:25 AM

Thanks for the reply. But I would like to point out that the manual says that Go-To accuracy will be affected and is the case for me.

I have Dec,09 CG-5 (firmware already latest) so the supplied manual was reflecting an older firmware. The manual on celestron site even with revisions appears a bit off ("Addendum to the Advanced GT mount manual (firmware v.4.10). This leaves the process a bit random it seems.

In case you are wondering about the UnSync, after a polar align (All-Star) feature, this is required or you will be locked in a certain part of the sky. (polar align uses your final Finder/Center Eyepiece/Center
to sync on that part which needs to be undone)

anwsers to your questions:

My Go-To works fine, Why things do not work
after a polar align I do not know. So you at least Know My methods for a Normal Go-To work, and I get around 3 min unguided for a polar align at 400mm for imaging so my Polar align works. For power I use and Outlet not a battery.
I use a 25mm Eyepiece (yes,yes I know) I dont have all night to find stars, and you know its working because my my go-to accuracy(before polar) and polar align work (imaging time).


Point out if you will, but 'tain't so.

Let me tell you a story. Just a couple of months back, one of the new guys in the club brought his CG5 out for the first time to our darksite. I was busy, so was the other guy out there who uses a CG5. We kept an eye on him and helped when we could. Several hours later NG comes over to my observing position:

"Unk Rod, can you help? My go-tos are great, but whatever I find don't stay in the eyepice long."

I gave his setup an eyeball. Yep, the CG5 put whatever I requested in the field of the C8 (at f/10). But the trackin' sucked. Hmmm... Then it dawned on me: Bubba had "polar aligned" on _Kocab_ instead of Polaris. :lol:

I have used all the firmware versions containing AllStar. If your go-to is good normally, but not after an AllStar Polar Alignment (which is NOT what I got out of the initial post), your problem is in syncing/realigning. In order to see if that is the problem, forget all the cotton-pickin' unsyncing and yadda-yadda-yadda.

Turn the mount off after you run Allstar and do a go-to alignment. Just a normal alignment with Cal stars.

Not exactly sure what you are doing firmware-wise, either. 4.10 DID NOT HAVE ALLSTAR. That began with v4.15. If you do indeed have 4.10 YOU CANNOT use Allstar--your HC don't have it--and you shouldn't follow those instructions in the manual. You will polar align using Polaris only and will follow the procedure in the polar alignment procedure in the Utility menu.

#8 deltav3

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Posted 11 February 2010 - 12:22 PM

Thanks for the reply. But I would like to point out that the manual says that Go-To accuracy will be affected and is the case for me.

I have Dec,09 CG-5 (firmware already latest) so the supplied manual was reflecting an older firmware. The manual on celestron site even with revisions appears a bit off ("Addendum to the Advanced GT mount manual (firmware v.4.10). This leaves the process a bit random it seems.

In case you are wondering about the UnSync, after a polar align (All-Star) feature, this is required or you will be locked in a certain part of the sky. (polar align uses your final Finder/Center Eyepiece/Center
to sync on that part which needs to be undone)

anwsers to your questions:

My Go-To works fine, Why things do not work
after a polar align I do not know. So you at least Know My methods for a Normal Go-To work, and I get around 3 min unguided for a polar align at 400mm for imaging so my Polar align works. For power I use and Outlet not a battery.
I use a 25mm Eyepiece (yes,yes I know) I dont have all night to find stars, and you know its working because my my go-to accuracy(before polar) and polar align work (imaging time).


Point out if you will, but 'tain't so.

Let me tell you a story. Just a couple of months back, one of the new guys in the club brought his CG5 out for the first time to our darksite. I was busy, so was the other guy out there who uses a CG5. We kept an eye on him and helped when we could. Several hours later NG comes over to my observing position:

"Unk Rod, can you help? My go-tos are great, but whatever I find don't stay in the eyepice long."

I gave his setup an eyeball. Yep, the CG5 put whatever I requested in the field of the C8 (at f/10). But the trackin' sucked. Hmmm... Then it dawned on me: Bubba had "polar aligned" on _Kocab_ instead of Polaris. :lol:

I have used all the firmware versions containing AllStar. If your go-to is good normally, but not after an AllStar Polar Alignment (which is NOT what I got out of the initial post), your problem is in syncing/realigning. In order to see if that is the problem, forget all the cotton-pickin' unsyncing and yadda-yadda-yadda.

Turn the mount off after you run Allstar and do a go-to alignment. Just a normal alignment with Cal stars.

Not exactly sure what you are doing firmware-wise, either. 4.10 DID NOT HAVE ALLSTAR. That began with v4.15. If you do indeed have 4.10 YOU CANNOT use Allstar--your HC don't have it--and you shouldn't follow those instructions in the manual. You will polar align using Polaris only and will follow the procedure in the polar alignment procedure in the Utility menu.



Forgot to say I am very sure I got the correct stars (in Eyepiece and Finder) I use a Skyscout and I know a few of them by name. (yes the skyscout does screw up sometimes, easily fixed)

I use the latest firmware, no I did not downgrade.

As for the Unsync option, you need to or you will be warned when you polar align to unsync. (depending on how you aligned w/ calib stars or not)

Thanks for the advice anyways. :cool:

#9 freestar8n

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Posted 11 February 2010 - 12:28 PM

Do you mean Normal Go-To + 2-3 Calib stars than polar align? I gave this a try before same result. Oddly enough once I can actually find another Messier object than Add that as a calb Object it seems to goto the other objects no problem, very strange. (This is after a polar align + 2 calib stars)



I would do the alignment and calibration carefully with 3 or 4 calibration stars. Do it carefully with crosshairs if possible. Don't align on Messier objects - only stars - and do it carefully, finishing with up/right.

That should make your GoTo as accurate as possible, so that your PA is then more accurate.

It sounds like your centering may not be as accurate as it could be, and your calibration isn't as good as it could be.

Frank

#10 deltav3

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Posted 11 February 2010 - 01:02 PM

Do you mean Normal Go-To + 2-3 Calib stars than polar align? I gave this a try before same result. Oddly enough once I can actually find another Messier object than Add that as a calb Object it seems to goto the other objects no problem, very strange. (This is after a polar align + 2 calib stars)



I would do the alignment and calibration carefully with 3 or 4 calibration stars. Do it carefully with crosshairs if possible. Don't align on Messier objects - only stars - and do it carefully, finishing with up/right.

That should make your GoTo as accurate as possible, so that your PA is then more accurate.

It sounds like your centering may not be as accurate as it could be, and your calibration isn't as good as it could be.

Frank


I make sure every time my stars in dead in the finder cross hairs (6x30) and in the eyepiece. I will give this another try tonight.

Thanks.

#11 mike174

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Posted 11 February 2010 - 02:45 PM

I'll be getting a SW EQ-5P and wonder if the setup is similar to the CG-5?

Tnx,

Mike

#12 rmollise

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Posted 11 February 2010 - 06:23 PM

[
As for the Unsync option, you need to or you will be warned when you polar align to unsync. (depending on how you aligned w/ calib stars or not)

Thanks for the advice anyways. :cool:


One last time and then I'll move on. If the polar alignment routine messes up the go-to, you are doing something wrong afterwards with regards to unsyncing. Polar align the mount. Turn it off. That won't harm your polar alignment. Then turn it back on and do a normal 2+4 alignment.

#13 freestar8n

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Posted 11 February 2010 - 06:43 PM

Rod-

He is talking about unsyncing AFTER doing AllStar polar alignment. In order to do AllStar you must sync on the polar alignment star. After you complete AllStar, you are still sync'd to that star. If you then go far from that star, you may be better off unsync'ing to improve GoTo accuracy. If you find your GoTo is still not great, you may choose to replace alignment stars - which requires an unsync anyway.

I think there is a misunderstanding here. You don't need a good polar alignment to have good GoTo - but you do need to do the polar alignment well, and ACHIEVE a good polar alignment, for GoTo to be good immediately after doing AllStar. The alignment should, and must, be good after allstar in order for you to have accurate GoTos without a new alignment - and good GoTos right after doing AllStar is a big advantage of AllStar.

Turning off the mount and starting over would defeat a lot of the purpose of AllStar, but you could do it if you want.

Frank

#14 Chris Rowland

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Posted 11 February 2010 - 06:43 PM

This is what I do after an AllStar polar align:


That's it, nothing.

I don't realign, replace alignment stars, replace calibration stars, undo sync, anything. I just use it - and I've no complaints about goto accuracy.

What I do do is a good alignment to start with, with two alignment stars and two or three calibration stars, using a reticle EP.

AIUI, if your gotos are good before you polar align they should be good afterwards. That's as long as the polar alignment adjustments are basically in azimuth and altitude and you centered the star both at the sync and polar alignment stages.

Chris

#15 joec33

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Posted 11 February 2010 - 07:53 PM

If you find you have to adjust the mount quite a bit during All-star polar align you should always shut the mount off and redo your 2 star alignment. Moving the mount to much using the alt and AZ adjustments will totally throw your goto's off. Your mount has no idea that it's being moved when you play around with anything but the controller simple as that. I just bought my mount in Dec also so we have the same firmware. If you just follow the steps I'm about to give you you'll be ready to image with perfect goto's. Going through the whole unsync and resync is a waste. 2 star align, 4 calibration stars, polar align, shut off mount and do it again. After your second polar align shut off the mount and do a 2 star align and 4 calibration stars and you will be ready to image. In no way do you have to go through all of this if your not imaging but since you are I highly recommend you do! This works great for me and most of the people I have talked to on this site that image using the cg5-gt mount.

#16 deltav3

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Posted 11 February 2010 - 09:11 PM

If you find you have to adjust the mount quite a bit during All-star polar align you should always shut the mount off and redo your 2 star alignment. Moving the mount to much using the alt and AZ adjustments will totally throw your goto's off. Your mount has no idea that it's being moved when you play around with anything but the controller simple as that. I just bought my mount in Dec also so we have the same firmware. If you just follow the steps I'm about to give you you'll be ready to image with perfect goto's. Going through the whole unsync and resync is a waste. 2 star align, 4 calibration stars, polar align, shut off mount and do it again. After your second polar align shut off the mount and do a 2 star align and 4 calibration stars and you will be ready to image. In no way do you have to go through all of this if your not imaging but since you are I highly recommend you do! This works great for me and most of the people I have talked to on this site that image using the cg5-gt mount.


Just wondering where are you getting this idea that the mount needs to be powered off realigned/ than polar aligned than powered off again. Was this a step of an older revision of the Cg-5 mount? (Mine is December 2009)

The manual for both the CG-5 and the CGEM mount (funny enough the CGEM lists exactly my aliment procedures under the polar align section) say BOTH contain NOTHING about powering off the mount and still retaining any alignment (which is why it is necessary to realign and add calib stars after a polar align)

#17 joec33

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Posted 11 February 2010 - 11:42 PM

You can reference the manual all you want friend. You can also use CAPITAL LETTERS all you want but it's not going to change the fact that your the one with the problem not me. Time and time again I have seen threads about how people set up this mount for imaging and it seems to always come down to this method. Take it or leave it. Night after night I use this method and my goto's place the objects I want to image right on my DSI's little ccd chip. Just give it a try next time your out, if it doesn't work then you can use your capital letters all you want.

ps. I bought my mount in December of 09' just like you.

#18 joec33

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Posted 12 February 2010 - 12:02 AM

Also I would stay away from using calibration stars that are to close to the east or west horizons, zenith or celestial pole.

#19 deltav3

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Posted 12 February 2010 - 12:37 AM

I just tried a 12mm Illuminated eyepiece and it appears to work better than before, go-to is now in the eyepiece after a polar align.

My steps:
2 star align, polar align, unsync, realign 2 stars, 1 calib star. puts m36,m37 NGC 869 into a 25mm eyepiece.

Thank You all for the help!

#20 freestar8n

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Posted 12 February 2010 - 07:52 AM

Your mount has no idea that it's being moved when you play around with anything but the controller simple as that.



The AllStar polar alignment procedure knows exactly how far the mount is being moved, because it knows how far off the alignment star is when it asks the user to adjust the mount. As long as the user does the physical work that AllStar requests, and theoretically it could be many degrees of motion, the mount knows where it was before the alignment, and where it is after the alignment - all without powering down and realigning.

But it's important that the mount be well aligned (but not well polar aligned) before the PA procedure, so the mount really does know how far off PA it is. This means the alignment/calibration prior to PA should be accurate and have many calibration stars.

After PA, check goto accuracy and, as needed, try unsyncing (if doing GoTo's far from the PA star) and then replacing alignment stars.

Powering down and starting all over should work fine - but the idea of AllStar is to avoid this.

Frank

#21 rmollise

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Posted 12 February 2010 - 09:24 AM

Rod-

He is talking about unsyncing AFTER doing AllStar polar alignment. In order to do AllStar you must sync on the polar alignment star. After you complete AllStar, you are still sync'd to that star. If you then go far from that star, you may be better off unsync'ing to improve GoTo accuracy. If you find your GoTo is still not great, you may choose to replace alignment stars - which requires an unsync anyway.

I think there is a misunderstanding here. You don't need a good polar alignment to have good GoTo - but you do need to do the polar alignment well, and ACHIEVE a good polar alignment, for GoTo to be good immediately after doing AllStar. The alignment should, and must, be good after allstar in order for you to have accurate GoTos without a new alignment - and good GoTos right after doing AllStar is a big advantage of AllStar.

Turning off the mount and starting over would defeat a lot of the purpose of AllStar, but you could do it if you want.

Frank


I'm not misunderstanding anything. If he has a problem with go-to accuracy following a polar alignment, he needs to eliminate problems involving unsyncing stars. Turing the scope off and realigning is how you eliminate that as a troubleshooting measure.

#22 wsuriano

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Posted 12 February 2010 - 09:44 AM

I am just wondering why the OP does not use three or more calibration stars before doing his AllStar Polar Alignment. I would not use APA until I got at least 3 calibration stars. I'm with Chris on this one. Once I do my alignment stars and then 3 or 4 calibration stars, followed by the APA, I'm good to go. My GoTos are spot on and I can easily get 5 minute guided subframes. If my GoTos are off after that, as Unk says, I've done something wrong on the front end. I'll shut down and start over making sure that I've got the right alignment and calibration stars in the right part of the sky.

Bill

#23 mayidunk

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Posted 19 February 2010 - 10:26 AM

Hi all, I'm new here, so I thought I'd say hello, and impose upon you just a little bit by relating to you my understanding of the CG-5 set-up and alignment procedures, just so I know that I understand what you guys are talking about.

By way of a little background, the only goto scope I'm familiar with is the Celestron Ultima 2000, which I've owned for many years. I also have a Vixen GP GEM that I use with my refractor, so I'm familiar with polar alignment. This mount is manual, so it doesn't have goto capability.

Anyway, after reading through the alignment procedures in the CG-5 User's Manual, I think I understand that there are at least three things that need to be done to insure the mount knows where it is, so that it can then take you where you want to go.

The first one is the mount calibration procedure, which lets the mount know it's datum points (Physical reference points on the mount itself.)

The second one is the set-up procedure, which tells the mount where on Earth it's physically located, and when in time it currently exists. (I'm surmising that, once the coordinates, date, and time have been entered, the mount then uses that data to build a virtual model of your local sky in it's memory, based upon ephemeris data it already has contained within itself.)

And, finally, the two-star alignment procedure, which the mount uses to confirm and refine the model of the sky that it previously built in its memory. Once this procedure is done, the mount should accurately slew to your selected object. However, it will track the object only as accurately as the mount is physically aligned with the Earth's rotational axis.

So, you then use the PA utility to increase the mount's tracking accuracy. It does this by guiding you to physically adjust the angle of the mount's Right Ascension (R.A.) shaft so that it's axis of rotation is parallel with where it thinks the Earth's rotational axis is located. I believe the PA utility does this by first slewing the OTA so that it is parallel with the R.A. shaft, and then allows you to center Polaris in the telescope's field of view by adjusting the R.A. shaft's angular position using the mount's altitude and azimuth adjustment screws.

Of course, if you make these adjustments, you will have then altered the sky model's orientation relative to the mount's physical datum points, because you adjusted the angular position of the R.A. axis in order to bring Polaris's real world position in line with where the mount expected it to be located. So...

You go back and do another two-star alignment, this time to allow the mount to readjust the sky model so that it's back in alignment with the mount. Once this is done, the mount should not only accurately slew to your selected object, it should also accurately track that object.

My question is... do I understand this correctly? Am I in the ball park? out to lunch?... Did you stop reading way before this? :D

Also, I noticed that the CG-5 doesn't seem to require leveling. My GP mount has a little bulls-eye level built into it. In order to get the best tracking accuracy, the mount must be leveled first, before it's polar aligned. Wouldn't this hold true for the CG-5 as well? Perhaps I missed something, and just glossed right over that part of the set-up procedure?

Thanks for your answers, observations, wisdom, and corrections! :)

Bob

#24 mclewis1

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Posted 19 February 2010 - 10:44 AM

Bob, Welcome to CN.

The manual situation is a bit mixed up for the CG-5 because of it's age. It all depends on which firmware level you have loaded in the hand controller. The hardware part of the manual doesn't change but for information about the hand controller (and this includes alignment procedures) then it's probably better to refer to additional manuals.

V3 - Original CG-5 manual
4.10 - Original plus v4 addendum
4.16 - CGEM or CGEPro manual

#25 anivision

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Posted 19 February 2010 - 11:44 AM

My question is... do I understand this correctly? Am I in the ball park? out to lunch?... Did you stop reading way before this? :D

I think you got it all pretty well. The difference between the older hand controls and the newer ones is, as mentioned above, the polar alignment procedure. In the older versions you did as you mentioned in your post, aligning to the polaris. It's just that the mount takes in concideration that polaris isn't quit the celestial pole.

In the newer version of the hand control there is a procedure called "all star polar alignment", ASPA, and with this you don't have to align through polaris anymore. You can choose any other bright star of your own desire, but then the procedure is much the same. You can say it slews to the position where your choosen star should have been IF the mount was polar aligned in a correct way.

I hope I didn't messed it up for you again :grin:






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