ICEINSPACE
Most Read Articles
Moon Phase
CURRENT MOON Waxing Crescent
11.8%
The Sun Now
Time Zones
Sydney*
8:13 am
Perth
5:13 am
Auckland*
10:13 am
New York
4:13 pm
Paris
10:13 pm
GMT
9:13 pm




Go Back   IceInSpace > Beginners Start Here > Beginners Equipment Discussions

Reply
 
Thread Tools Rate Thread
  #1  
Old 13-08-2018, 10:09 PM
Hemi
Registered User

Hemi is offline
 
Join Date: Dec 2010
Location: Darwin
Posts: 165
AZEQ6 polar alignment and goto woes

Dear Members,

Iíve had the mount for a month or two and has been purely used in az mode for visual...replacing my evolution mount. Itís been fine in AZ, but gotos have not been great.

In any case, I thought I would Learn to use it in eq. This is my first eq mount, and Iím struggling.
Iím using the sw WiFi dongle, and the SynScan pro app for all mount commands.

Iíve leveled the tripod with a spirit level. Marked a line southward on the floor with the dec offset, and aligned the mount to south. I start at the home position with scope south and counter weights down. Latitude is set using an inclinometer.

I complete a 3 star alignment....only the 3rd slew gets me close to the alignment star, otherwise the first two are at least to full large telrad circles away. Alignment completes successfully. I then do the polar alignment routine....choose a star and then follow the instructions to re centre using az or alt knobs.

The problem is asjustment of the knobs never centers the star. The routine asks that you use only the az adjustment and then only the latitude adjustment.

Sorry for the long post and I hope Iím making sense.

Thanks in advance for any insights to what Iím doing wrong.


Cheers

Hemi
Reply With Quote
  #2  
Old 14-08-2018, 06:51 AM
Zuts
Registered User

Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,421
Hi,

I am trying the same thing and have the same issue. The other issue is that if you are too far out in RA then you run out of adjustment room on the RA bolts.

I only tried once but after reading a bit I think that it should be done iteratively. Other people seem to do it two or three times then it seems to work.

Next time I plan to run the routine and only worry about RA and manually swivel the mount until South is pretty good and I have good adjustment room in the RA bolts; then run the routine 3 or 4 times, each time power cycling the mount after going to home position.

I only do a two star alignment, usually on alpha crucis and alpha centauri which only takes about a minute, next time I will also use a 12mm reticle.

On my previous foray into DSO AP I got good results using drift alignment, that was 10 years ago though and this time I want something quicker than the 40 or so minutes that took me.

That's my theory anyway, if anyone else has any ideas I would also be pleased to here them.

Cheers
Paul
Reply With Quote
  #3  
Old 14-08-2018, 07:09 AM
TareqPhoto (Tareq)
Registered User

TareqPhoto is offline
 
Join Date: Oct 2017
Location: Ajman - UAE
Posts: 145
I am use a Polemaster, and it is like a life saver, but i can't comment about using it for southern skies, in my sky i use Polaris just easy because it is just right in front of me high enough, nothing covering it unless clouds or smoke or weather condition such as haze and alike.


I have issues with the mount last year, but i learnt more and more every time, and sounds i am doing fine with the mount, i even damaged the mount [the internal motherboard only] by an accident from overpowering and fixed it with new mount motherboard, now it is working fine, but what i found is that i couldn't have any longer exposures now no matter what i did or how good my PA is, now maximum i get is 3minutes, last year without accurate PA i can accidentally get 4-5 minutes unguided, now even guided i can't get over 3 minutes, someone said that could be over weighted the setup, not sure if that is the case.


Many said they take 5 minutes with Polemaster, i take 10 minutes because i am not good in things not in my language, also wanted to do things more carefully and gently slowly so i know nothing wrong will happen, but i feel that i will never get good with my setup and mt AP will be always low level or not great results, only so so, but solar system imaging sounds fine because it doesn't depend on single long exposures frames, i really feel crazy about seeing others using AZ-EQ6 with really long exposures or even lesser mounts such as EQ5 or AVX, means either i have something wrong or they are genius.... OR the stars are frozen for them and not for me.
Reply With Quote
  #4  
Old 14-08-2018, 08:25 AM
Hemi
Registered User

Hemi is offline
 
Join Date: Dec 2010
Location: Darwin
Posts: 165
Thanks Guys,

Tareq: Alas I am 12S and have no view of the SCP from my location
Zuts: How do you get ACrux and A Centauri as options for the 2 star! I always get difficult ones....not sure how to manually choose stars that are not listed.
Alignment on Celestron was much better IMO. Will try repeated iterations, but still confused: Do you mean get it close as you can, but not necessarily in the EP?

Cheers

Hemi
Reply With Quote
  #5  
Old 14-08-2018, 08:43 AM
Zuts
Registered User

Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,421
Quote:
Originally Posted by Hemi View Post
Thanks Guys,

Tareq: Alas I am 12S and have no view of the SCP from my location
Zuts: How do you get ACrux and A Centauri as options for the 2 star! I always get difficult ones....not sure how to manually choose stars that are not listed.
Alignment on Celestron was much better IMO. Will try repeated iterations, but still confused: Do you mean get it close as you can, but not necessarily in the EP?

Cheers

Hemi
Hi,

I am running latest firmware and they are available for selection on my handset.

I mean guestimate the amount required for the first ra movement after running the routine and noting how far the scope slews for the adjustment and then physically rotating the mount, then re-level.

Also, I have a Baader 60 mm raci finderscope with a decent reticle. So I may try the routine with that. It shouldnt really matter what you are looking through as it's the mount you are trying to align.


Cheers
Paul
Reply With Quote
  #6  
Old 14-08-2018, 10:03 AM
Wavytone (Nick)
BigBanger

Wavytone is offline
 
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 3,355
Hemi,

There are options to filter stars used for alignment in the manual see sections 7.1-7.3. https://inter-static.skywatcher.com/...61208V1-EN.pdf

The next issue is whether you have set elevation limits - see section 6.2 of the manual - eg nothing below 15 degrees of the horizon. If so this will limit the stars available for alignment. You might like to disable this.

I normally do the mechanical alignment of the mount within using a calibrated Clinometer app to set the elevation, and using the dec circle to set the azimuth of the mount using a known bright star due east or west - set the dec axis and clamp it so it indicates the declination of the star, the adjust the azimuth of the mount and RA to align on the star - do NOT adjust the declination !

As reported at the end of the SynScan software alignment routine I’m regularly achieving this within 15 arc min of the pole.

During the SynScan alignment sequence it is important to align to the selected star accurately. The better you do this the better your GOTOs will be.

The errors in subsequent GOTOs will be no less than the inaccuracies you had in the alignment routine. So if you just eyeballed it with a finder, you can expect GOTO errors of a degree or more.

On mine I put a crosshair eyepiece in my main scope and align on the crosshairs to within 1-2 arc minutes. Subsequent GOTOs are good enough to put the scope within 15 arc min of the target - which I suspect is the resolution of the encoders in the mount. Important, because with a focal length of 3100 the field of view is only 30 arc min anyway.

Then last issue is cone error in the mount ie perpendicularity of the axes, and between the dec axis and the optical axis of the scope. If this is off by as much as a degree the GOTOs will be similarly inaccurate. It pays to measure and correct this, but that’s a whole story on its own.

Last edited by Wavytone; 14-08-2018 at 10:28 AM.
Reply With Quote
  #7  
Old 14-08-2018, 03:54 PM
Hemi
Registered User

Hemi is offline
 
Join Date: Dec 2010
Location: Darwin
Posts: 165
Thanks Wavytone,
I use my mobile phone with an inclinometer app, do you think thats enough? I use a 20mm crosshair EP for the alignment.

For the bit about known star declination, im not sure I understand....I presume you first have to setup home position as outlined by the astronomy shed video. ie level RA and Dec, pointing South. Set the declination to the known star and then use the AZ and RA to get the star to the EP? is that right??

Cheers

Hemi
Reply With Quote
  #8  
Old 14-08-2018, 04:44 PM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney
Posts: 399
Hi Hemi,
Iím a retired newbie , only had my HEQ5 Pro with a 6Ē newt 6 months and can get my PA error down to 12 arc seconds on my Synscan handcontroller after 4 or 5 iterations ( half an hour to an hour ) and only do a 2 Star alignment , you donít need 3 Star itís all in whatís Stars you select inside the same side of the meridian. My mount always ends up within cooee of the object through the finder.I do both visual and astrophotography
To find true south or SCP I ditched my expensive Silva compass and used the good olí Sun ( solar noon meridian method ) never fails and gets me very close to SCP meridian line ( I can post a separate procedure if you are interested , costs $10 and takes 10 minutes )
Then level the mount using a good Stanley boat type bubble level ( I have a digital inclinometer but only use it for altitude setting on the mount , I found better results using the bubble level )
Balance the mount in both axis
Power up, enter data in Synscan, 2 star align and PA align using the Synscan PA routine as I have no view of SCP ( I use an Orion 20mm 70deg illuminated reticle eye piece with a 2.5 x Televue powermate and defocus the Star into a small donut for really good accuracy) I have tried drift aligning but it takes so long and you have a limited selection of stars near the meridian and celestial equator, I get quicker a better results using the Synscan PA routine. Eventually I will PA on my laptop

Anyway clear skies and good luck ( itís never easy but eventually you nail it )
Reply With Quote
  #9  
Old 14-08-2018, 10:24 PM
Hemi
Registered User

Hemi is offline
 
Join Date: Dec 2010
Location: Darwin
Posts: 165
Thanks Martin....I hope I get there in the end, very frustrating when you think youíve got all the steps nailed down. Iím primarily visual, but felt the need to get eq mastered, for my own satisfaction really. Will plod on. I would be very interested in the solar meridian method.

Cheers

Hemi
Reply With Quote
  #10  
Old 15-08-2018, 09:22 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney
Posts: 399
Hi Hemi,
Attached is a copy of my procedure of finding true South using the Solar Noon meridian method
I find this method very accurate for EQ mounts when star aligning and polar aligning
I threw my Silva compass in the bin

Apologies for the number of files ( 4 off )

Good luck
Martin
Attached Thumbnails
Click for full-size image (AEA2D9F9-A785-40E6-90F9-FEF8C151EC7E.jpg)
130.4 KB35 views
Click for full-size image (E8A8C407-1827-4627-8CE0-FD7BA8D3798D.jpg)
142.1 KB29 views
Click for full-size image (65717C49-5668-4C78-973F-79FA19CDB7B4.jpg)
144.5 KB30 views
Click for full-size image (FB2F1E64-0BE7-4232-A84C-1BE9EC891033.jpg)
86.6 KB27 views
Reply With Quote
  #11  
Old 19-08-2018, 10:21 PM
Hemi
Registered User

Hemi is offline
 
Join Date: Dec 2010
Location: Darwin
Posts: 165
Thanks everyone,

Martin, I havenít gotten round to your method yet.
Wavy, Iíve leveled my scope pretty accurately so the setting circles in home position should point the scope at the pole if NS aligned. I took your advice and just slewed to a star from there, and adjust the mount to get the star in view.....great tip and obvious in hindsight, it gets you roughly there abouts.

Zuts, your spot on, itís an iterative process once your nearly there....I 2 star aligned and then used the polar align routine a couple of times, each time the az and alt corrections got the star closer and closer to the centre of the eyepiece. Itís currently approximately centre of a 12mm eye piece.

....deep sigh!

The gotos are still not great, but Iíll work on that next. Once Ive got it all perfect, Iíll go back to AZ!

Cheers

Hemi
Reply With Quote
  #12  
Old 20-08-2018, 07:12 AM
vlazg's Avatar
vlazg (George)
Registered User

vlazg is offline
 
Join Date: May 2014
Location: Darwin
Posts: 517
Hemi, using your mobile near the mount is not a good idea , the circuit and metal of the mont causes quite a degree of error in the accuracy of the results.
Reply With Quote
  #13  
Old 20-08-2018, 10:19 AM
Hemi
Registered User

Hemi is offline
 
Join Date: Dec 2010
Location: Darwin
Posts: 165
Thanks George,

im only using a mobile for the inclinometer, not the compass, I thought that was ok.

I was going to PM you, as I realised your from Darwin and have seen your amazing images on this site and on AstroBin. Do you use an AZ EQ6?

Best

Hemi
Reply With Quote
  #14  
Old 20-08-2018, 10:39 AM
vlazg's Avatar
vlazg (George)
Registered User

vlazg is offline
 
Join Date: May 2014
Location: Darwin
Posts: 517
Quote:
Originally Posted by Hemi View Post
Thanks George,

im only using a mobile for the inclinometer, not the compass, I thought that was ok.

I was going to PM you, as I realised your from Darwin and have seen your amazing images on this site and on AstroBin. Do you use an AZ EQ6?

Best

Hemi
Yes mate, I use an AZEQ6 but I use it for imaging and use computer software for polar alignment, Either Sharpcap which I find very good or Polemaster. I haven't used the hand controller in years.
Reply With Quote
  #15  
Old 20-08-2018, 11:28 AM
Kunama (Matt)
Reducing the Clutter.....

Kunama is offline
 
Join Date: Sep 2012
Location: Garran ACT
Posts: 3,556
I use an AzEQ6 in ALT-Az mode only but find that the choice of alignment stars makes a huge difference to subsequent GoTo performance.

My 2-star alignment routine is to choose two stars at least 25ļ altitude, up to 75ļ and separate in azimuth by 90ļ-120ļ. For really accurate stuff I use alignment stars on the same side of the sky that I am going to be viewing...
Reply With Quote
  #16  
Old 20-08-2018, 03:56 PM
Wavytone (Nick)
BigBanger

Wavytone is offline
 
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 3,355
Hemi, there's also a "Pointing Accuracy Enhancement" function described in the Synscan manual section 11.2:

I suspect few use it because of where its buried in the menus, and its a tad fiddly in the dark with the 2 second wait in step 3:

1. Perform a 1-star alignment, 2-star alignment, or a 3-star alignment.
2. Choose a celestial object in a zone of interest as reference by referring to a sky map or planetarium software. In general, it is a rather bright star, but users can also use other objects. Use the SynScan hand control to control the mount to point the telescope to the reference object.
3. Use one of the following operations to start the PAE calibration:
• Press the “UTILITY” shortcut key, access to sub-menu “PAE\PAE Correction”, and then
press the ENTER key.
• Press and hold the ESC key for two seconds.
4. The screen will display “Re-centering Obj.:” in the first row, and display the name of the reference object in the bottom row. (If the last object is launched from a PC, then instead of the name of the reference object, it will display “The last target”.) Now use the direction keys of the hand control to center the object in the telescope’s FOV, and then press ENTER to confirm. Remember to end the centering operation by pressing the Right and Up direction keys together.
5. Repeat Step 2 to 5 for viewing different portions of the sky.

Note:
• Whenever the SynScan hand control locates an object, it will automatically check whether any PAE calibration data is available, and apply the compensation accordingly. No manual intervention is required.
• If multiple PAE calibrations are performed in the same zone, the previous calibration data will be overwritten.
• Users can access the menu “UTILITY FUNCTION > PAE > Clear PAE data” to clear all PAE calibration data.
• The PAE calibration data will be automatically cleared after a 1-star alignment, 2-star alignment or 3-star alignment.
Reply With Quote
  #17  
Old 28-08-2018, 09:32 AM
Hemi
Registered User

Hemi is offline
 
Join Date: Dec 2010
Location: Darwin
Posts: 165
Slow but steady progress

Thanks Nick,

I think Iím reasonably polar aligned...mechanically, the polar routine gets the star bang in the middle of a cross hair EP.

Iíve setup using the SW WiFi adapter and iOS app. And the SynScan mobile ascom driver. So canít seem to find a PAE option. Nor will it give me sensible alignment Stars. In any case alignment is ok. (Do I need two telrads on my scope? One alignment star always puts the finder where no finder should ever go! This EQ stuff is a lot of hassle)

Sharp cap is up and running with a asi 294 on my c925 (currently at native FL), astrotortilla and Allstar plate solver loaded, and sharpcap solving and talking to mount...all via ascom and wireless.

The kicker you ask? Well any exposure of more than a few seconds gets star trailing! Got me beat so far! I know, I must not be polar aligned. But I canít be that far off! I could get longer exposures with my AZ evolution mount.

What do I try next folks?

All the best

Hemi
Reply With Quote
  #18  
Old 28-08-2018, 12:29 PM
middy's Avatar
middy
Registered User

middy is offline
 
Join Date: Feb 2006
Location: Brisbane
Posts: 612
Are you sure your latitude is entered correctly? You haven't missed the minus sign for southern latitudes? I was just thinking about what you said earlier about not having acrux as an option for star alignment. If it thinks you are north of the equator then it may not display the more southern stars in the list. Just a thought.
Reply With Quote
  #19  
Old 28-08-2018, 12:55 PM
Hemi
Registered User

Hemi is offline
 
Join Date: Dec 2010
Location: Darwin
Posts: 165
Hey Middy,

I donít set anything, the mount gets its info from the phone. But Iíve checked and lat is correct.

Hemi
Reply With Quote
  #20  
Old 28-08-2018, 07:23 PM
Zuts
Registered User

Zuts is offline
 
Join Date: Mar 2007
Location: sydney
Posts: 1,421
Hi,

Not sure if this is that helpful but..

When you think you are polar aligned, align the scope in the home position and take a photo. If you upload it to http://nova.astrometry.net it will plate solve for you and show you where in the sky you are pointing, plus give you a map of your field of view with objects of interest marked (e.g. the scp). You should be able to see if you are actually in the ball park.

Cheers
Paul
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 07:13 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Advertisement
NexDome Observatories
Advertisement
SkyWatcher WiFi Adaptor
Advertisement
SkyWatcher 2018 Catalogue
Advertisement
Atik Horizon
Advertisement
FLI Cameras and Imaging Accessories
Advertisement
Interest Free Finance
Advertisement
Lunatico Astronomical
Advertisement
Bintel
Advertisement
OzScopes Authorised Dealer
Advertisement
Astronomy and Electronics Centre
Advertisement