Celestron Advanced avx GoTo Two Star Alignment - Forums

Topic starter

Apr 3, 2020

Dear astro photographers

I don't konw if I should write in English or in mother tongue German. I'll try in English:

I have purchased a TS Optics 192/520 refractor and the Celestron AVX mounting. I now have tried 6 times to do the Two Star Alignment, but as a result I always have the desired object out of the viewing field of the 25mm eyepiece. I follow the instructions consquently:
Tripod in level, orientated to North with a compass, introduction of the local time and timezone 1 (Switzerland), daylight savings, the coordinates of my spot, the date in the right sequence. I then center each of the two stars first in the finderscope and then in the eyepiece with the help of the handcontroller, finally I chose two more stars. After the alignement is completed, the object is quite a bit on the left of the telescope. Even two resettings to the manufacturer's settings did not help.

As a newbie I'm looking for help. I thank you in advance for this!

Kind regards

Markus

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Rich Sky

Apr 3, 2020 · Edited: Apr 3, 2020

Hello Haaven, I have an Evo and a CGX, but not your mount typwe, however, the nexstar controler is more or less the same depending on the firmware loaded.

Try the following:

Curious to know, what firmware do you have loaded, hand controler push logo and key 9, i think ?

1- Ensure the hand controler setup is using the option 'equatorial' (not alt-az) and 'sidereal'. You may or may not have this option based on the firmware of your hand controler. Thus, my question above.

2- Ensure to push the button goto switch position and then start your alignment. Your scope should point to Polaris, before alignment.
The leg of your mount, and weights should be pointing North, near Polaris and at switch position, the scope is aligned with the leg and weight…

3- Make sure to use the right star, when doing your alignment. It is possible to pick the wrong star and get 'alignment success', however the sky model is wrong and your scope will not find anything.
For example, you select Caph as part of your model, and with your starfinder, you think you are at Caph, but you have selected a star near Caph, the end result will be mis-alignment.

-To deal with this issue, you can, after the alignment is completed, use Star, and select the star that was used in your Alignment. If your scope does not return to the same star, selected, your alignment is wrong.

That's all I can think of, at this time.

Good luck, and keep looking up.

R

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Markus

Topic starter

Apr 3, 2020

Dear R

Many thanks for your help! I have just checked the Handcontroller and set to EQ-North (which was not set). But I don't see which button you mean when telling me to push "goto switch position".
It's a very helpful advice to select the used star during alignment once tis is done. I will try this. And yes, it's dificult for a beginner to get the right star in the finderscope. I have a Omegon Microspeed Guidescope 50mm, but also the Omegon LED Finder with the red dot, but I haven't tried it yet.

Kind regrads
Markus

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Rich Sky

Apr 3, 2020 · Edited: Apr 3, 2020

Dear RMany thanks for your help! I have just checked the Handcontroller and set to EQ-North (which was not set). But I don't see which button you mean when telling me to push "goto switch position".
It's a very helpful advice to select the used star during alignment once tis is done. I will try this. And yes, it's dificult for a beginner to get the right star in the finderscope. I have a Omegon Microspeed Guidescope 50mm, but also the Omegon LED Finder with the red dot, but I haven't tried it yet.

Kind regrads
Markus

Hi Markus, please re-read my post, I added one line regarding the north alignment of your equipment.

Goto switch position is my option on the CGX mount, on yours, do you have a 'Goto Home button'?

The goto home button, brings the scope to RA=0 or Polaris... It will set the scope aligned with the north leg (the home position)... if I can describe it this way.
One more thing, have you set the correct Mount altitude adjustment knob specific to your location?

Markus

Topic starter

Apr 3, 2020 · Edited: Apr 3, 2020

Hi again, and thx again!

The tripod is correctly levelled and the leg is pointing to North. When I start the alignment process, the controller asks me to align the mount to the home position (RA and DEC aligned to the marks). I follow this instruction. I don't have a specific "Goto Home button".

Yes, I have set the correct altitude on the mount. I even have looked through the hole and could see polaris.

Kind regards

Markus

Rich Sky

Apr 3, 2020

Ok, that is the switch or go home position, that is good.

One more thing, have you set the correct Mount altitude adjustment knob specific to your location?

Markus

Topic starter

Apr 3, 2020

Hi!

Yes, I have set it to the correct altitude of my spot and I could see Polaris through the hole in the mount where the polfinder would be.

Markus

Rich Sky

Apr 3, 2020 · Edited: Apr 3, 2020

Ok, so, when you press 'home position' can you see Polaris in your finderscope? and or your eyepiece?

If you do, perhaps the issue was with selecting equ North option.

give it a try ( do a 2 stars alignment) and let us know

Clear skies

Markus

Topic starter

Apr 3, 2020

Hi again!

Yes, that's what I will do and I'll come back. Unfortunately, I'm not able to try this evenening, but if the weather is ok, I will try again tomorrow.

Many thanks for your help!

Kind regards

Markus

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Rich Sky

Apr 3, 2020

Ok Markus,
Don't give up, what is ahead is fantastic!
good luck and keep looking up!

UlfG

Apr 3, 2020

Hi,
I have found that it greatly helps to add a third calibration star to the two star alignment. When the two star alignment is done, the hand controller asks (at least the version I have) if you want to add a calibration star. Do that, follow the instructions, and in my experience this will greatly improve the accuracy. I have used the AVX for a couple of years, and I quickly found that using only two stars is just not enough. As I remember it, the manual recommends using at least one extra calibration star. I my opinion, it is also easier to find the correct stars using a red dot finder rather than a finder scope, but that might be a matter of personal opinion.
Regards
Ulf

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Rich Sky

Apr 3, 2020

A typical Celestron finderscope

Fred

Apr 4, 2020

Hello,

Make sure your finderscope is accurately aligned with your telescope. Polaris is a good way to check this and this should also be your home position. When I do the 2 star alignment, I always follow with a 4 star calibration. It only takes a few minutes and each calibration star increases the accuracy. Any slop in your star diagonal and eyepiece will also introduce error. If you can remove the star diagonal while doing the alignment you may improve the accuracy but you may find yourself in some awkward positions. If the telescope does not slew anywhere close to the first alignment star then you probably have entered the time or location wrong in the initial settings.

Fred

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Markus

Topic starter

Apr 4, 2020

Dear friends

I could not answer earlier because for an unknown reason my account was desactivated.

Many thanks for your advices! I will give it a try this evening although the moon will be quite bright. But practising is important…

I always added two calibration stars after the two star alignment. I guess that my problem is to point at and to center the right star. I have been reading quite a lot yesterday and today and I have decided to try out the red spotted LED finder instead of my finderscope. Maybe this will help me. This afternoon, I have checked the alignment of this finder and also of my finderscope.

I wish you a nice saturday evening and a sunny sunday. Stay safe…

Markus

Markus

Topic starter

Apr 4, 2020

Dear R
Dear Fred

The old man is so happy: it worked! Wow, it's such a great feeling watching the telescope slewing to the chosen object and having it nearly perfectly centered.

Before starting the Two Star Alignment, I open the menu, go to "Tracking" and set "EQ-North". I don't know why this is not saved. After the Two Star Alignment, I chose 4 calibration stars. I find it much easier to operate with the red spotted LED finder. I believe these two factors (EQ-North and finding the right stars) went wrong the other evenings. The next excercise will consist in trying to shoot my first pictures.

Many thanks again!

Kind regards
Markus

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Fred

Apr 4, 2020

Hello Markus,

Congratulations, it is a steep learning curve but it is great to hear that you are up and running now.

Now go out and have fun.

Fred

Rich Sky

Apr 5, 2020 · Edited: Apr 5, 2020

Before starting the Two Star Alignment, I open the menu, go to "Tracking" and set "EQ-North". I don't know why this is not saved. After the Two Star Alignment, I chose 4 calibration stars. I find it much easier to operate with the red spotted LED finder. I believe these two factors (EQ-North and finding the right stars) went wrong the other evenings. The next excercise will consist in trying to shoot my first pictures.

Hi Markus,

Glad for you it worked.
Now, if I may. Try to develop a 'routine', same steps, every time, all the time, over and over for your star alignment. That way, you will succeed every time!

Enjoy your scope and the skies.

R
PS. over time, you will see that you don't need to do, too many calibration stars. I only do one and I get excellent tracking ~0.6 to 1" error in PHD. Right now, doing 4 calibration stars, is good practice for you

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Markus

Topic starter

Apr 5, 2020

Hi Folks!

Thanks for your encouragements! I appreciate the advice for installing a routine. It seems to me I already have some… I'm ready to gou out although the moon is bright. But I want to prctise, and if the alignement works - why should it not

- I want to try to take the first pictures… without any expectations, just to give it a try.

Have a nice evening

Markus

Rich Sky

Apr 5, 2020

At this point, your passion is driving the train.
The optical train, that is!
Keep looking up!

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David Redwine

Apr 6, 2020

Rich Sky:
The goto home button, brings the scope to RA=0 or Polaris…

The AVX does not have a "goto home" button. It has marks on the RA and Dec axis that you have to line up manually before you start your alignment.

Well Written Concise

Markus

Topic starter

Apr 8, 2020

Dear friends!

Last Sunday I made my first picture (Orion Nebula). The principal aim was to practise setting up the mount and using the autoguiding. I made 20 subs and 5 darks, everything went well! Ok, the picture is not very good, the moon was bright and I'm not quite sure how to postprocess. I'm used to prepare my pictures in LR and PS, but I don't know other editing software. So I have stacked my RAWs in DeepSkyStacker and then postprocessed in LR and PS. At this point, I'm npot sure if I should work on my RAW before stacking them and if yes at which point.

Is there any other specific software for astrophotography?

Kind regards
Markus

Respectful Engaging

Rich Sky

Apr 8, 2020 · Edited: Apr 8, 2020

There are many available software, but I use startools. I stack with DSS, darks, flats, biases and lights and then process with startools.
Simple and was easy for me to learn.
You can try it for free, go to the link below.

link to startoolsClear skies

Christoph Lichtblau

IOTD Staff

Apr 9, 2020

Hallo Markus,

Wie hast du denn die Montierung exakt eingenordet? Gibt es denn kein Polarfinderscope in deiner Montierung? Wenn ja? Ist es exact calibriert? Durch ein Loch zu schauen langt bei weitem nicht aus beim einnorden. Der Polarstern läuft ja bei einer Erddrehung eine Kreisbahn ab.

Markus

Topic starter

Apr 9, 2020

Christoph Lichtblau:
Hallo Markus,Wie hast du denn die Montierung exakt eingenordet? Gibt es denn kein Polarfinderscope in deiner Montierung? Wenn ja? Ist es exact calibriert? Durch ein Loch zu schauen langt bei weitem nicht aus beim einnorden. Der Polarstern läuft ja bei einer Erddrehung eine Kreisbahn ab.

Lieber Christoph
Ich danke Dir für Deine Hilfe! Aus den oben stehenden Einträgen kannst Du sehen, dass ich die Einnordung in den Griff bekommen habe. Ich habe statt des 50mm Finderscopes einen LED Leuchtpunktsucher montiert und kann damit viel besser den richtigen Stern anvisieren. Das war offensichtlich mein Problem.

Liebe Grüsse

Markus