Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Polar Aligning with Celestron Nexstar 6se plus a Wedge

astrophotography accessories eq beginner reflector dslr observing
  • Please log in to reply
42 replies to this topic

#1 lo12310

lo12310

    Lift Off

  • -----
  • topic starter
  • Posts: 15
  • Joined: 13 Jul 2019

Posted 15 July 2019 - 10:53 PM

I've recently tried to polar align with the Celestron 6se and a wedge. I aligned the wedge to the north celestial point pretty well but when I performed an eq north alignment, the Goto was not as accurate as I was hoping meaning it got to the general correct area but it would always consistently be off by a little bit. It would really be helpful if anyone can give me a detailed step by step procedure on how to do a polar alignment with a wedge. And yes my tripod is level.



#2 Dynan

Dynan

    Mercury-Atlas

  • *****
  • Posts: 2839
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 15 July 2019 - 11:24 PM

Celestron has a built in All Star Polar Alignment. It gets you very close, especially if you have a reticle eyepiece.

 

If you have an imaging camera, SharpCap is a great program. But as I said, it requires a compatible camera.



#3 lo12310

lo12310

    Lift Off

  • -----
  • topic starter
  • Posts: 15
  • Joined: 13 Jul 2019

Posted 16 July 2019 - 04:38 PM

My hand control doesn't have all star polar align.



#4 Don W

Don W

    demi-god

  • *****
  • Administrators
  • Posts: 23171
  • Joined: 19 May 2003
  • Loc: Wisconsin, USA

Posted 16 July 2019 - 04:41 PM

Actually it does. I'm moving this to the Nexstar section for better coverage.



#5 Michael_Swanson

Michael_Swanson

    Vanguard

  • *****
  • Posts: 2294
  • Joined: 23 Apr 2003

Posted 16 July 2019 - 08:39 PM

My hand control doesn't have all star polar align.

From my book, The NexStar User's Guide II:

 

All-Star Polar Alignment (sometimes referred to as ASPA) is Celestron’s marketing

name for a wedge alignment routine that allows you to use almost any bright star

as a reference point. This name is found in the some of the newest manuals but not

in the hand control menu.

 

Polar Alignment with the NexStar+ Hand Control
 

Procedure
• Complete an EQ alignment, as described in the previous section.
• GoTo an alignment star on the Named Star list (found on the STARS button).
• Press ALIGN, scroll up/down to select Polar Align, and press ENTER.
• Scroll up/down to select Align Mount and press ENTER.
• At this point, the mount will again GoTo the star you selected. Center the star in
the finder and press ENTER.
• Using the same arrow buttons as used during alignment, center the star in the
eyepiece and press ALIGN. The star is now synced.
• Following the instructions on the display, press ENTER to begin the final steps
of the procedure. The mount will slew slightly to an orientation that corresponds
to a correct polar alignment.
• Using only the wedge adjustments, not the arrow buttons on the hand control,
center the star in a reticle or high magnification eyepiece. Press ENTER when
finished.
• Press BACK once, scroll up/down to select Undo Sync and press ENTER. If you
escaped out of the menu system, you will find Undo Sync on the ALIGN button
menu.

 

Additional Tips
• For additional accuracy, some prefer to repeat the EQ alignment followed by
another All-Star Polar Alignment.
• When selecting the star for All-Star Polar Alignment, select a star high in the sky
and near the meridian, but not directly overhead and not near the celestial pole.
• You may wish to use Display Polar Alignment Error (later in this section) to see
the results before and after using All-Star Polar Alignment.

 

Best regards,
Mike Swanson
Author of "The NexStar Users Guide II"
Author of "The NexStar Users Guide"
Author of "NexStar Observer List"
https://www.nexstarsite.com


  • Dynan and Biofish like this

#6 Dynan

Dynan

    Mercury-Atlas

  • *****
  • Posts: 2839
  • Joined: 11 Mar 2018
  • Loc: NOLA

Posted 16 July 2019 - 09:27 PM

Rule #1 for Celestron Nexstar telescopes - Always listen to Michael Swanson...

Rule #2 See rule #1


  • ShaulaB, MJB87 and BigKahuna like this

#7 Biofish

Biofish

    Lift Off

  • *****
  • Posts: 14
  • Joined: 22 Jun 2019
  • Loc: Chattanooga, TN

Posted 16 July 2019 - 11:39 PM

Had the same issues tonight as the OP and will try to adopt the All Star Polar Align tomorrow night. (hopefully ending without a rant which I assume is why my thread was deleted)

 

Thank you for the information.



#8 Michael_Swanson

Michael_Swanson

    Vanguard

  • *****
  • Posts: 2294
  • Joined: 23 Apr 2003

Posted 17 July 2019 - 12:00 AM

Hi Biofish,

 

Not sure what happened to your other post but I did reply to it :-)  

 

It would be good if we know what model of scope you have.  Some people add that info to their "signature" (in your user profile) here in Cloudy Nights.

 

Best regards,
Mike Swanson
Author of "The NexStar Users Guide II"
Author of "The NexStar Users Guide"
Author of "NexStar Observer List"
https://www.nexstarsite.com


Edited by Michael_Swanson, 17 July 2019 - 12:01 AM.


#9 Biofish

Biofish

    Lift Off

  • *****
  • Posts: 14
  • Joined: 22 Jun 2019
  • Loc: Chattanooga, TN

Posted 17 July 2019 - 12:09 AM

 

It would be good if we know what model of scope you have.  Some people add that info to their "signature" (in your user profile) here in Cloudy Nights.

 

I have a Nexstar 6 with an SE mount. I have never had trouble aligning it with 2 star.
Recently I decided to get better subs for AP and bought the wedge.  Like the OP, I would North EQ align and then do a polar alignment, but my goto was off.. by quite a bit. I did it several times but never got very good alignment.

I have never tried the all star polar align, (as detailed from your book above) and never knew it was even an option!... so I will try that tomorrow night.
I appreciate your patience with newcomers like me.



#10 Noah4x4

Noah4x4

    Vanguard

  • *****
  • Posts: 2482
  • Joined: 07 Apr 2016
  • Loc: Colchester UK

Posted 17 July 2019 - 12:11 AM

I now use a Starsense ASPA (very precise!) and have not used a Nexstar + HC for some while. But my recollection was I generally had to repeat the complete procedure described by Mike Swanson at least twice (sometimes thrice) to ensure sufficient convergence to produce an acceptable tiny Polar Algnment Error (PAE).

 

The problem being my human clumsiness within a mechanical procedure. The final adjustments required are fine and even a one eighth (over) turn is suffice to throw you out. By repeating the procedure, you simply tighten up the PAE. It is significantly easier with Starsense but make sure your firmware post dates January 2018 as there was in infamous bug before that. Even with the Nexstar HC, ensure firmware is up to date as there have been numerous remodelling.

 

Soft earth into which your tripod might sink can be a problem. I build a triangular wooden jig to support my tripod that spread the load over soft ground. Even a two millimetre sink can throw you out.. When applying force to turn the often stiff wedge knobs means you need a lot of skill to avoid movement in your rig. Whilst I mastered the Nexstar + HC procedure whilst Starsense had the ASPA/bug, I have since embraced Starsense and it's auto-polar align is excellent (But not available via Tablet/APP, but can be performed via CWPI). 


Edited by Noah4x4, 17 July 2019 - 12:14 AM.

  • Biofish likes this

#11 lo12310

lo12310

    Lift Off

  • -----
  • topic starter
  • Posts: 15
  • Joined: 13 Jul 2019

Posted 17 July 2019 - 12:30 AM

Thank you for the procedure Micheal Swanson. I do recall doing an eq alignment and polar mount alignment but I never did the eq alignment twice. I'll let you know how it goes on my next clear night.



#12 Biofish

Biofish

    Lift Off

  • *****
  • Posts: 14
  • Joined: 22 Jun 2019
  • Loc: Chattanooga, TN

Posted 17 July 2019 - 12:30 AM

I now use a Starsense ASPA (very precise!) 

I was considering getting StarSense. Do you disconnect it after alignment if you want to use a guidescope?  Or is the guiding with the wedge good enough for AP?



#13 mikenoname

mikenoname

    Messenger

  • *****
  • Posts: 476
  • Joined: 29 Jan 2015
  • Loc: Death Valley Region (Bortle 2 - SQM 21.9+)

Posted 17 July 2019 - 10:38 AM

I now use a Starsense ASPA (very precise!) and have not used a Nexstar + HC for some while. But my recollection was I generally had to repeat the complete procedure described by Mike Swanson at least twice (sometimes thrice) to ensure sufficient convergence to produce an acceptable tiny Polar Algnment Error (PAE).

 

The problem being my human clumsiness within a mechanical procedure. The final adjustments required are fine and even a one eighth (over) turn is suffice to throw you out. By repeating the procedure, you simply tighten up the PAE. It is significantly easier with Starsense but make sure your firmware post dates January 2018 as there was in infamous bug before that. Even with the Nexstar HC, ensure firmware is up to date as there have been numerous remodelling.

 

Soft earth into which your tripod might sink can be a problem. I build a triangular wooden jig to support my tripod that spread the load over soft ground. Even a two millimetre sink can throw you out.. When applying force to turn the often stiff wedge knobs means you need a lot of skill to avoid movement in your rig. Whilst I mastered the Nexstar + HC procedure whilst Starsense had the ASPA/bug, I have since embraced Starsense and it's auto-polar align is excellent (But not available via Tablet/APP, but can be performed via CWPI). 

 

Very interesting.

 

I knew StarSense could fully automate your star alignment, but I had no idea that it could also automate the All-Star polar alignment as well. Looks like I have some research to do. Noah, what is your set up procedure when setting up your scope using StarSense and how long would you estimate it takes you in total to do it?



#14 Noah4x4

Noah4x4

    Vanguard

  • *****
  • Posts: 2482
  • Joined: 07 Apr 2016
  • Loc: Colchester UK

Posted 17 July 2019 - 02:56 PM

Very interesting.

 

I knew StarSense could fully automate your star alignment, but I had no idea that it could also automate the All-Star polar alignment as well. Looks like I have some research to do. Noah, what is your set up procedure when setting up your scope using StarSense and how long would you estimate it takes you in total to do it?

Starsense ASPA Procedure for Northern Hemisphere;

 

1. Set OTA at regular index marks. OTA will be horizontal.

 

2.  Set wedge to your latitude.

     The mount arm will now be leaning backwards (OTA aimed upwards).

 

3.  With OTA still at index marks, now aim OTA South along NS meridian. Note NOT North!

      To achieve this, lift and rotate entire assembly (tripod). Keep OTA at Index Marks.

     The OTA will now be aimed at the SOUTHERN Meridan with mount aim leaning backwards towards North.

 

4.  Let Starsense perform a regular auto- align.

5.  Let Starsense perform an ASPA ( instructions in HC)

      During ASPA follow HC guidance to adjust wedge knobs.

6.  Conclude with a regular auto-align

 

Above assumes Starsense was prior calibrated. Total elapsed time, less than five minutes.


  • mikenoname and Dynan like this

#15 lo12310

lo12310

    Lift Off

  • -----
  • topic starter
  • Posts: 15
  • Joined: 13 Jul 2019

Posted 17 July 2019 - 06:05 PM

I have used the starsense for all star polar aligning before but when it slews so far away from a star for aligning, its impossible for me to turn my wedge in az to get it back on the scope. I think starsense doesnt have an option for wedge users. It thinks you have an eq mount.



#16 Michael_Swanson

Michael_Swanson

    Vanguard

  • *****
  • Posts: 2294
  • Joined: 23 Apr 2003

Posted 17 July 2019 - 07:05 PM

I have used the starsense for all star polar aligning before but when it slews so far away from a star for aligning, its impossible for me to turn my wedge in az to get it back on the scope. I think starsense doesnt have an option for wedge users. It thinks you have an eq mount.

Two things:

  • Be sure your StarSense hand control (HC) is running the latest firmware.  Instructions for update here: https://www.nexstars...NexStarPlus.htm
    ASPA was broken in StarSense until a somewhat recent firmware update.
  • ASPA doesn't care if you are using a fork mount on a wedge or a German EQ mount.  If you are too far out from a correct polar alignment to reach the correct point via the azimuth wedge adjustments, you simply must move the tripod.  That would be the same no matter what your method for polar alignment.  A trick you might try is to point the scope straight up (parallel to the fork arms) prior to even powering up and get Polaris in the field of view of a moderate magnification eyepiece by leaving the wedge's azimuth in the middle and moving only the latitude adjustment on the wedge and physically moving the tripod.  Sorry, no similarly easy way to do this in the Southern Hemisphere so physically moving the tripod during your first ASPA is about as easy as possible for folks down under.

Best regards,
Mike Swanson
Author of "The NexStar Users Guide II"
Author of "The NexStar Users Guide"
Author of "NexStar Observer List"
https://www.nexstarsite.com



#17 mikenoname

mikenoname

    Messenger

  • *****
  • Posts: 476
  • Joined: 29 Jan 2015
  • Loc: Death Valley Region (Bortle 2 - SQM 21.9+)

Posted 17 July 2019 - 09:58 PM

 

5.  Let Starsense perform an ASPA ( instructions in HC)

      During ASPA follow HC guidance to adjust wedge knobs.

 

Noah,

 

Thanks for the great info!

 

In your first post you indicated that you don't use an HC anymore and seem to indicate that CPWI is what you use. Does the software have a polar align feature like the polar align tool in SharpCap? Is using the software for this procedure better than the HC?



#18 Noah4x4

Noah4x4

    Vanguard

  • *****
  • Posts: 2482
  • Joined: 07 Apr 2016
  • Loc: Colchester UK

Posted 18 July 2019 - 03:16 PM

You can use (one of)  Starsense HC or CPWI for a Starsense ASPA, but not yet with tablet/phone. CPWI is great for remotely controlled rigs from an indoors 'mission control'. Both work fine. I don't use Sharpcap, so can't comment about that. 

 

Yes, lo12310, sometimes the polar alignment error (PAE) to be eliminated can place your calc-star way outside your eyepiece FOV. I bought an illuminated cross hair 9 x 5 RACI finderscope to assist with pulling it back into view. However, if you very carefully PRIOR align your scope as accurately as possible along the N-S Meridian using a decent magnetic compass the typical PAE error is much smaller. The manuals talk about a "rough placement" along N-S. I found the more accurate you achieve, the less work you will have to do pulling your calc-star back.

 

The fact that the initial PAE might be large is why you may need to repeat the procedure. If a huge number of knob turns are required, the risk of accidently moving tripod (or it sinking in soft earth) increases. This procedure, even with Starsense takes a lot of user skill. As Mike Swanson says, it's the same procedure for GEM or Alt-Az + wedge. I use the latter, and get great tracking results, but I do have an Evolution (e.g. metal spur gears, less prone to backlash etc). I can't comment whether Starsense + Wedge or Starsense + GEM is easier as I don't own a GEM. But Starsense (IMHO) makes wedge polar alignment easier. 



#19 mikenoname

mikenoname

    Messenger

  • *****
  • Posts: 476
  • Joined: 29 Jan 2015
  • Loc: Death Valley Region (Bortle 2 - SQM 21.9+)

Posted 18 July 2019 - 06:32 PM

You can use (one of)  Starsense HC or CPWI for a Starsense ASPA, but not yet with tablet/phone. CPWI is great for remotely controlled rigs from an indoors 'mission control'. Both work fine. I don't use Sharpcap, so can't comment about that.

 

Thanks again.

 

I kind of answered my own question. Because SS doesn't actually transmit any pictures to your PC, a SharpCap-style PA is not possible. Michael's post above (#5) details how SS does it.

 

How often do you find yourself having to repeat the ASPA to get a good polar alignment?


Edited by mikenoname, 18 July 2019 - 06:56 PM.


#20 lo12310

lo12310

    Lift Off

  • -----
  • topic starter
  • Posts: 15
  • Joined: 13 Jul 2019

Posted 19 July 2019 - 08:38 PM

Correct me if im wrong. So i should first point my wedge north and roughly polar align towards Polaris or better with the telescope tube pointed upwards. Then I perform an EQ north alignment. I then select Polar alignment on HC and perform a mount alignment. Then i turn telescope on and off and perform another EQ north alignment. 


  • Biofish likes this

#21 lo12310

lo12310

    Lift Off

  • -----
  • topic starter
  • Posts: 15
  • Joined: 13 Jul 2019

Posted 19 July 2019 - 08:47 PM

https://drive.google...iew?usp=sharing

 

 

Wondering if this is how the  telescope should look when roughly polar aligning to celestial north. This diagram took me many hours to make so be nice.



#22 lo12310

lo12310

    Lift Off

  • -----
  • topic starter
  • Posts: 15
  • Joined: 13 Jul 2019

Posted 19 July 2019 - 11:53 PM

Ok i just had a telescoping session and i performed all of the procedures i mentioned above. The tracking is still not 100 percent but some goto objects are better than others. I did some 1 minute exposures of the dumbbell nebula but i was getting star trailing in every shot. I have a starsense and i think i might switch to that. Should that help?



#23 donel

donel

    Sputnik

  • *****
  • Posts: 47
  • Joined: 25 Apr 2019
  • Loc: RB Community in San Diego

Posted 20 July 2019 - 06:06 PM



Wondering if this is how the telescope should look when roughly polar aligning to celestial north.

I think you have it backwards. The hing on the wedge should point north. With the marks lined up the tube should point to the CE.

#24 Biofish

Biofish

    Lift Off

  • *****
  • Posts: 14
  • Joined: 22 Jun 2019
  • Loc: Chattanooga, TN

Posted 20 July 2019 - 09:19 PM

https://drive.google...iew?usp=sharing

 

 

Wondering if this is how the  telescope should look when roughly polar aligning to celestial north. This diagram took me many hours to make so be nice.

Here ya go.

 

Mount_North_South_large.jpg?v=1537309346



#25 Noah4x4

Noah4x4

    Vanguard

  • *****
  • Posts: 2482
  • Joined: 07 Apr 2016
  • Loc: Colchester UK

Posted 21 July 2019 - 02:10 AM

Here ya go.

 

Mount_North_South_large.jpg?v=1537309346

This diagram is correct for a Starsense ASPA in the Northern Hemisphere. The lean is dictated by your Latitude setting on the wedge. But as I said before, during this set up, try to get your OTA closely aligned along an imaginary line through N-S. Use a compass. A degree or two off this imaginary line will increase your Polar Alignment Error (PAE) and mean more wedge turns are required. Repeating the ASPA might be necessary for convergence to minimise PAE.

 

What confuses everybody are the diagrams in the Nextar and CPC  instruction manuals that show a set up whereby the OTA initially points towards Polaris. That predates ASPA procedures. It's time Celestron updated its manuals! 


Edited by Noah4x4, 21 July 2019 - 02:16 AM.

  • Biofish likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics





Also tagged with one or more of these keywords: astrophotography, accessories, eq, beginner, reflector, dslr, observing



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics