That old chestnut - polar alignment

[AlistairHowie]

Well .... that wasn't a very good start to viewing last night with my new AZ-EQ6GT mount ... my first ever GEM.

So this is how my attempt at polar alignment went ...

• Challenge #1 - not realising that the counterweight bar when stored in the mount obscures the polar scope. Took 15 minutes to work that out.
  
• Challenge #2 - not realising that the reticle illuminates if I power the mount up. Took 10 minutes to realise that
  
• Challenge #3 - figuring out the handset to dim the reticle without a manual. Another 5 minutes
  
• Challenge #4 - not realsing that I shouldn't actually be able to see Ursa Major in the polar scope EP at the same time as Polaris, just look at its orientation outside the polar scope (is that the same for Cassiopia - I presume so?). About 20 minutes
  
• Challenge #5 - getting my eye up against the polar scope EP - why don't they make them with right angles??? Very uncomfortable crounched down in the mud, with a tripod leg right underneath the scope. Why wouldn't they make it so a single tripod leg faces north, so there are two behind the mount, giving enough space to get your head down and your eye up against the polar scope??
  
• Challenge #6 - correctly identifying Polaris, let alone positioning it in the right place. The stars didn't seem that bright or clear, and I couldn't be sure I was looking at Polaris. I ended up shining my LED torch on a focused beam through the polar scope EP and I was able to see the beam shining up on Polaris, but when I looked through the polar scope I still got confused as to what I was looking at. I've now realised that the image was probably inverted as well!
  

I thought it was going be a quick 15 minutes outside having a play with polar alignment so I wasn't dressed for the weather, and gave up cold, shivering and frustrated, after about an hour of trying to align.

I think I know the theory of aligning reasonably well, so any thoughts, hints or tips on the actual experience of aligning would be appreciated. Thanks

[Catweazel]

Hi Alistair, looking at your post, I couldn't understand how the counterweight obscures the polar scope; the scope is above the counter weight bar?

I have never used an illuminated retiucule, but with mine I go out about 20 mins before it actually gets dark, and Polaris is really obvious, as it's the only star in that direction that is bright enough to see. If you are unable to get out that early, then Polaris is in a straight line from the lowest 2 stars in Cassiopia. It can be a pain, as Polaris isn't that bright a star, but after a few tries it does get easier, as you become more familiar with the stars around it. I agree about right angled polar scopes, it would make life a lot easier; I kneel on a bin bag to get under the scope

[whooshbang]

Challenges 1,2,3,4 and 6.

I feel your pain

[Guest]

...then Polaris is in a straight line from the lowest 2 stars in Cassiopia...

Cassiopia? Did you mean The Plough?

http://www.astro-etwinning.org/images/navigation/Polaris-finding-Cassiopea.gif

[AlistairHowie]

Hi Alistair, looking at your post, I couldn't understand how the counterweight obscures the polar scope; the scope is above the counter weight bar?

I have never used an illuminated retiucule, but with mine I go out about 20 mins before it actually gets dark, and Polaris is really obvious, as it's the only star in that direction that is bright enough to see.

Good advice, thank you. If it's a weekend, I'll bear that in mind. Otherwise, it'll be setting up in the dark, I'm afraid. I know where Polaris is, I don't have a problem with that. My issues seems to be a view through the polar scope which didn't obviously (to me, at least) have Polaris clearly standing out, or which didn;t correspond to the night sky! Practice, I guess!

Re the counterweight bar, I don't know about other GEMs, but on the new EQ6 it is "captive", and stored in the head of the mount, where it does obscure the axis of the polar scope. Once I undo a screw, it is then free to pull/fall out into position, unblocking the view.

[AlistairHowie]

Perhaps my problem was that I was intently looking for the constellations in the wrong place. Can someone just confirm for me ....

• Should I actually be able to see Cassopeia or the Plough in the reticle when aligning on Polaris?
  
• If yes, will the images be inverted and/or reversed?
  
• If no, and they are just for reference when looking outside the polar scope, should I be aiming to place them in an inverted position? What I mean is, last night the Plough was nearest the horizon and Cassopeia was up high. When I'm roating the mount in RA to get the stars correctly oriented, should I be putting Cassopeia down low and the Plough up high, or has the reticle been corrected to allow for that?
  

Hopefully that makes some sense.

[Guest]

No, you will not see either through the reticle of the polar scope.

The image will be reversed

If plough high visually then it should be low in the reticle.

[Guest]

You may find this of use: http://myastroimages.com/Polar_FinderScope_by_Jason_Dale/

[AlistairHowie]

No, you will not see either through the reticle of the polar scope.

The image will be reversed

If plough high visually then it should be low in the reticle.

So the image is INVERTED, if the Plough should be high in the EP when visually low. Is it also REVERSED?

You may find this of use: http://myastroimages..._by_Jason_Dale/

Thank you. I'd come across that program before but not downloaded it on the basis that my Synscan controller will give me the position of Polaris as a clockface time. Does that do the same thing as the Jason Dale program?

[themos]

The constellations in the reticle correspond to what you would see with the naked eye, I believe. So, if the Plough appears in the north-east and "vertical" to the naked eye, rotate the mount in RA until the reticle shows the Plough to the right and vertical.

[atmenterprises]

This all sounds too close to what I dealt with last night! And it doesn't help that there are two huge trees where Polaris is in the sky!

[Guest]

So the image is INVERTED, if the Plough should be high in the EP when visually low. Is it also REVERSED?

Thank you. I'd come across that program before but not downloaded it on the basis that my Synscan controller will give me the position of Polaris as a clockface time. Does that do the same thing as the Jason Dale program?

It will not be reversed just inverted. That is the Jason Dale Program.

[whooshbang]

I don't believe the image on the polar scope reticle is reversed.

You will not be able to see the constellations in the polar scope reticle due to a narrow field of view.

What you need to do is point your polar scope in the direction of Polaris, when you see a star appear in the polar scope it will more likely than not be polaris. Adjust your alt/az screws on the scope to centre it in the crosshair. Next using one eye to look through the polar scope and the other eye to look at the sky, rotate the scope in the RA axis until their positions match up. i.e if plough is up higher than Cassiopeia in the night sky, then the plough will be higher than Cassiopeia in your polar scope too.

Get them in the same position by rotating the RA Axis. when they look the same adjust your alt/az screws to put Polaris in the small circle drawn in the polar scope. You will have good alignment after this. It takes a bit of getting used to... good luck

[K3ny0n]

• Challenge #1 - not realising that the counterweight bar when stored in the mount obscures the polar scope. Took 15 minutes to work that out.
  
• Challenge #4 - not realsing that I shouldn't actually be able to see Ursa Major in the polar scope EP at the same time as Polaris, just look at its orientation outside the polar scope (is that the same for Cassiopia - I presume so?). About 20 minutes
  
• Challenge #6 - correctly identifying Polaris, let alone positioning it in the right place. The stars didn't seem that bright or clear, and I couldn't be sure I was looking at Polaris. I ended up shining my LED torch on a focused beam through the polar scope EP and I was able to see the beam shining up on Polaris, but when I looked through the polar scope I still got confused as to what I was looking at. I've now realised that the image was probably inverted as well!
  

All of the above - Applicable to me.

Rob.

[kirkster501]

On the Skywatcher NEQ6/HEQ5 forgetting to pull out the weight bar and wondering why you can't see Polaris. Had me stumped for 10 minutes last night....!

[Catweazel]

Cassiopia? Did you mean The Plough?

http://www.astro-etw...g-Cassiopea.gif

Yep! Sorry, I mean the Plough

[AlistairHowie]

Oh this is all soooooooo funny. All across the land, others with more experience than me are facing the same problems! That's just given me the renewed zest that I need to go outside now and see what I can manage tonight! I'll update in due course!

Thanks for all the help and advice.

[starman1969]

I'm fairly new to polar aligning and I had a problem finding Polaris through my polar scope.

Although I know exactly where Polaris is, when I look through the polar scope other stars seem to appear from nowhere.

I just try to align the brightest one, which should be Polaris.

Once I've done it a few times I should hopefully be able to learn the other stars' positions.

[Guest]

When I first started out I would find Polaris with my spotting scope and then centre it in main OTA before looking through polar scope for polaris. helped a lot.

[themos]

It helps also if you level the mount using the bubble. Then, once you've found Polaris one night, you can be sure you have at least the altitude correct the next night. It's then a question of lifting two legs of the tripod and "aiming" the axis of the mount towards Polaris, as you hold the tripod from the south side.

[AlistairHowie]

When I first started out I would find Polaris with my spotting scope and then centre it in main OTA before looking through polar scope for polaris. helped a lot.

Good idea, I like that!

It helps also if you level the mount using the bubble. Then, once you've found Polaris one night, you can be sure you have at least the altitude correct the next night. It's then a question of lifting two legs of the tripod and "aiming" the axis of the mount towards Polaris, as you hold the tripod from the south side.

Also a good idea. Thank you!

So ... I went outside again and things seemed to be much easier tonight - I wasn't so cold, I extended the tripod legs all the way down this time, meaning I didn't have to grovel in the dirt, and I remembered to extend the counterwight shaft! I shone my led torch through the polar scope, moved the mount a little until it hit Polaris, and then looked through the scope. I saw a bright star in the field of view, which I presume was Polaris! I loosened the RA clutch and rotated the mount so the Plough was in the same approximate position as I could see visually, and that put the Polaris circle in same place as the Synscan controller told me previously on powering up.

The challenge tonight was then to place Polaris into that circle using the jackscrew and the az adjustment screw. What I naively thought was that I'd use the jackscrew first to place Polaris vertically in the right position, and then use the az screws to move it horizontally into the small circle. Well, I should have known it wouldn't be that easy, Polaris didn't want to move simply right and left with the az screw movements, there was a bit of vertical motion as well. Anyway, to cut a long story short, I'm pretty sure that I managed to Polar align my mount, although by the time I did it the position of Polaris doubtless moved some way from where I was centering it! Oh well, practice makes perfect, right?

So just a few follow-up questions ...

1. Using the jackscrew to wind the mount up and down vertically was nice and easy, but using the az screws to move it horizontally was difficult - really tight to turn them (I did loosen the opposite bolt). Is that other people's experience?
   
2. I haven't yet made sure that my polar scope is aligned with the RA axis of the mount - I'll get to that in daylight at some point - but is my experience of finding it not quite so easy to move Polaris into its circle normal? I get the feeling it's probably like trying to adjust a finder scope with six adjustable screws
   
3. And lastly, for AP when I eventually get to it, I know drift alignment is what is required, but out of interest, if you get a "not bad" polar alignment with the polar scope, can guiding correct the remaining errors (assuming you're not trying to image at severla meters focal length?
   

Thanks again.

[Guest]

I set the p[olar scope using the polar scope finding software. then you need to adjust the azimuth and elevation to put the star in the circle. Don't just use the azimuth to try and get polaris in the circle. If the rotation of the polarscope is set correctly then adjust the two axes and all will be well

[Guest]

Have you seen this: http://www.astro-baby.com/HEQ5/HEQ5-1.htm

[Astro_Baby]

Read the manual is my advice, its pretty good for the AZ6

[AlistairHowie]

Have you seen this: http://www.astro-bab...HEQ5/HEQ5-1.htm

Now that IS helpful! Thanks.

Read the manual is my advice, its pretty good for the AZ6

Actually, I find your tutorial much more helpful! Thank you for writing it up. BTW, my Stellarvue 50mm finder/guider arrived yesterday. I was going to buy it anyway, but your review was the clincher .... so thanks again. A really nice piece of kit!