Alignmaster - how accurate is it?

[joecoyle]

I must be doing something seriously wrong then. I run through the Celestron all star polar align routine twice (same stars). The most I can get is 3 minutes guided subs. 

 

What am I doing wrong?

cheers

Joe

[Physopto]

On ‎06‎/‎04‎/‎2016 at 10:28, Davey-T said:

Yes, SW Star Adventurer 

On another subject, I'm getting a 10Micron GM 1000HPS  soon, how good does the PA have to be ?

Dave

Hi Dave,

Have a look on the 10 micron website. You can download the 1000 instruction manual there. It will tell you all about the alignment and what is satisfactory. It is very easy to get very good polar alignment, and does not take long at all.

Derek

 

[Davey-T]

My iEQ gives a polar alignment error after a two star align, if I do another two star align without altering anything it comes up with a different error 

Dave

[Physopto]

Quote "Next, I fired up AlignMaster, and selected two stars - Caph and Pollux. Caph was low on my visible horizon, so getting that through the murk (and my dodgy eyes) was a challenge, but anyway, we got there..."

It may be the atmospheric effects at low angles  as it effects the real angle you see the stars at.

[perfrej]

On 2016-04-06 at 11:28, Davey-T said:

Yes, SW Star Adventurer 

On another subject, I'm getting a 10Micron GM 1000HPS  soon, how good does the PA have to be ?

Dave

Dave,

The HPS series mounts will track perfectly well unguided with a few degrees of polar misalignment, so basically you want it as good as the rotation you are willing to accept. I usually go for an arc-minute or so and often end up at 30" or less if I iterate twice. It all takes just a few minutes - of time.

As stated here on the forum before, my 2000 in Provence had the bad luck of my drilling the holes in the pier-top rotated a bit too much west so I couldn't get any better than 52 arc-minutes. It still tracked perfectly well unguided for four months or so before I could get down and re-drill. In other words: don't worry too much about it.

 

/per

[daz]

Nice diagram Physopto!

[PeterCPC]

On 07/04/2016 at 14:00, joecoyle said:

I must be doing something seriously wrong then. I run through the Celestron all star polar align routine twice (same stars). The most I can get is 3 minutes guided subs. 

 

What am I doing wrong?

cheers

Joe

Then you are doing something wrong. When I used ASPA I could get 10 minutes easily. I would suggest that after your ASPA you are not doing the update alignment routine. It's essential to do that. Also use an illuminated reticule eyepiece to get it all perfectly centered. I used this check list when I did ASPA - it might help. Updating star alignment -

1. Press align - undo sync - enter

2. Slew to one of the initial alignment stars

3. Press align - alignment stars - select star

4. Centre star - enter - align

5. Repeat for other alignment stars

6. Slew to bright star on opposite side of Meridian

7. Press align - calib stars - enter

8. Centre star - enter - align

9. Press back - align - Polar Align - Display Align (this will show your true PA)

 

 

Peter

 

 

[Physopto]

3 hours ago, daz said:

Nice diagram Physopto!

It is not mine just one I thought explained it as simply as possible.

Derek

[joecoyle]

Hi Peter

yes I only just read that in the manual but even doing that doesn't help much.

i use my CCD camera and centre it in the reticle on my capture software. I'm guessing that's ok?

how many calibration stars have you been adding? I tend to do 3. 

Thanks

Joe

[PeterCPC]

I always use an EP but camera should be fine. I only ever added 2 calib stars and it all worked ok. How up to date is the firmware? Maybe that could be an issue.

Peter

[Astrofriend]

Hi Joe,

 

The drift align can be a bit confusing sometimes. But when it works it's really fast and precise.

I have done a tutorial on my homepage, maybe it could be of help?

http://astrofriend.eu/astronomy/tutorials/tutorial-drift-align/tutorial-drift-align.html

 

BR

/Lars

 

[joecoyle]

Thanks Lars I'll give it a read. 

 

Joe