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Visual Tutorial Polar Alignment for Dummies - Autoslew


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#1 astrosirius

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Posted 09 March 2016 - 03:43 PM

Dear to everybody.

 

I have made this simply but easy tutorial to following the steps to get the Polar Alignment with Autoslew.

 

I have noticed that there are many people with doubts how to proceed with the Polar Alignment, thus I have decided to make it to help all everybody that need it this help.

 

If you have considered that there is something wrong or need some amendment, please fell free to contact with me to update it.

 

Note: I have written "Dummies" to justify that is easy to understand for all levels especially for beginners.

 

I hope it be usefull.

 

Best regards
Luis Romero.

www.astrosirius.org

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Edited by astrosirius, 09 March 2016 - 04:02 PM.


#2 GeorgeCarey

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Posted 09 March 2016 - 05:27 PM

Thanks Luis. All very helpful to the beginner.
It is strange that the part about encoder resolution still appears - even with mounts with fixed encoder resolutions.

ASA DDM60Pro, homemade 8" and 10" reflectors, QSI 683 camera, Astrodon 5nm filters, Pulsar dome observatory. Website: http://www.geoastro.co.uk


#3 astrosirius

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Posted 09 March 2016 - 06:02 PM

Thanks Luis. All very helpful to the beginner.
It is strange that the part about encoder resolution still appears - even with mounts with fixed encoder resolutions.

Thank you George,

 

Yes you are right, the problem is that to do this tutorial I have installed in another computer so I have had to restart everything, for sure if you mount is fixed this message won't appear. I will take into consideration for my next update.



#4 GeorgeCarey

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Posted 09 March 2016 - 06:10 PM

It does appear. My mount went back to ASA last year for repair. When it came back I had to do a polar alignment, and even though I have fixed encoders I still got the message.

ASA DDM60Pro, homemade 8" and 10" reflectors, QSI 683 camera, Astrodon 5nm filters, Pulsar dome observatory. Website: http://www.geoastro.co.uk


#5 nakbrooks

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Posted 09 March 2016 - 06:13 PM

Just a quick question. How accurate do most people try and get their physical polar alignment (particularly for static installations) before doing Autoslew polar alignment? Autoslew obviously compensates for imperfect physical alignment, but there are limits. Presumably if it is sufficiently imprecise then rotational effects will cause a problem on long exposures at longer focal lengths?

This is of interest to me because I use the DDM85XL with the equatorial pier and physical alignment requires the whole pier to be adjusted - not easy. Just wondering how good is good enough. My F/L is 3,200mm.
Nigel Brooks
Stratis Observatory, Hautes Pyrénées, France.
http://www.facebook.com/stratisobservatory

#6 lukepower

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Posted 09 March 2016 - 06:28 PM

Hi Nak,

I am running at a focal of 3412mm so this might help you. According to Autoslew i am off by about 12'x8', and still get good 20 minute subs.
Once i was at over one degree off, that was too much :P

Lukas Demetz
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www.skygemsobservatories.com
Astro Dolomites Observatory, Skygems Network
Santa Cristina Valgardena, Italy
20" Cassegrain-Newton on ASA DDM85XL


#7 nakbrooks

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Posted 09 March 2016 - 07:32 PM

Hmm, I'll do well to match that. That's about 0.25mm of adjustment on the bolts. Difficult as with this pier you have to adjust in 3 dimensions (Alt, Az and E/W cant), all with several 100kg loaded.
Nigel Brooks
Stratis Observatory, Hautes Pyrénées, France.
http://www.facebook.com/stratisobservatory

#8 MarkS

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Posted 09 March 2016 - 11:05 PM

With my mobile set-up, at my usual locations, I get physical PA initially within about 10', and after physical trimming via 3star same DEC/ Polar Align routine <2' - usually (but not necessary) <1'.

 

I'd have thought that with a fixed installation one would get physical alignment down to ~1' or better - recognising that it can be difficult with heavy loads, but not impossible.

 

Mark



#9 astrosirius

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Posted 10 March 2016 - 11:19 AM

Just a quick question. How accurate do most people try and get their physical polar alignment (particularly for static installations) before doing Autoslew polar alignment? Autoslew obviously compensates for imperfect physical alignment, but there are limits. Presumably if it is sufficiently imprecise then rotational effects will cause a problem on long exposures at longer focal lengths?

This is of interest to me because I use the DDM85XL with the equatorial pier and physical alignment requires the whole pier to be adjusted - not easy. Just wondering how good is good enough. My F/L is 3,200mm.

 

Hi Nak, I have using the DDM85XL with an GSO RC14" truss (F/L 2848 mm), thw CCD is the Moravian G2-8300 (5,4um), currently I am working with an Astro Physics CCD tele compressor CCDT67, so my resolution is 0.54"/px (2065 mm). Once I made the PA I got 12'x6', I am working with 10 min with "MLPT" without troubles, taking into consideration good seeing.

 

Best regards

Luis 



#10 astrosirius

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Posted 10 March 2016 - 11:24 AM

It does appear. My mount went back to ASA last year for repair. When it came back I had to do a polar alignment, and even though I have fixed encoders I still got the message.

Thank you George for your updated. I will take it into consideration!!



#11 lukepower

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Posted 10 March 2016 - 12:52 PM

Nak,

I have about 125kg of equipment on the mount, plus counterweights and the mount itself. East-west correction is easy, the altitude one was nightmare ;₩

Lukas Demetz
------------
www.skygemsobservatories.com
Astro Dolomites Observatory, Skygems Network
Santa Cristina Valgardena, Italy
20" Cassegrain-Newton on ASA DDM85XL


#12 MikePaling

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Posted 14 January 2017 - 09:24 AM

Dear to everybody.

 

I have made this simply but easy tutorial to following the steps to get the Polar Alignment with Autoslew.

 

I have noticed that there are many people with doubts how to proceed with the Polar Alignment, thus I have decided to make it to help all everybody that need it this help.

 

If you have considered that there is something wrong or need some amendment, please fell free to contact with me to update it.

 

Note: I have written "Dummies" to justify that is easy to understand for all levels especially for beginners.

 

I hope it be usefull.

 

Best regards
Luis Romero.

www.astrosirius.org

Hi Luis ....

Your PDF was really useful for me when I first set up my DDM60 a few months ago ..... my system is now up and running and fully functional.

 

Just out of interest did you ever get around to making a second PDF that was promised at the end of your first PDF to show the next stage? It would have been useful .... and would still be useful for any future total novices that come along.

 

Mike






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