Polemaster - problem with precise alignment

[Andyb90]

Hi all,

I was out imaging last night and trying out my new polemaster for the second time. I was following the alignment steps on screen and everything seemed fine. I got polaris right in the center of the round target for the rough polar alignment.

However when I came to precise alignment and clicked the 'start monitor' button the two white squares with crosshairs in them kept moving around and the green pole target also kept moving. I tried to adjust the alt az bolts, but it was impossible to get the green square over the red axis.

It's odd as I don't remember having this issue when I first used the polemaster. I was able to overlay the green square on the red target with no issues at all.

Would appreciate any help on how to resolve this issue. I'm a bit perplexed at why it worked the first time but not this time.

Andy.

[RayD]

1 minute ago, Andyb90 said:

Hi all,

I was out imaging last night and trying out my new polemaster for the second time. I was following the alignment steps on screen and everything seemed fine. I got polaris right in the center of the round target for the rough polar alignment.

However when I came to precise alignment and clicked the 'start monitor' button the two white squares with crosshairs in them kept moving around and the green pole target also kept moving. I tried to adjust the alt az bolts, but it was impossible to get the green square over the red axis.

It's odd as I don't remember having this issue when I first used the polemaster. I was able to overlay the green square on the red target with no issues at all.

Would appreciate any help on how to resolve this issue. I'm a bit perplexed at why it worked the first time but not this time.

Andy.

I think that can happen with poor seeing Andy.

[sloz1664]

Hi Andy,

Yep it's definitely the quality of the skies. Some days the alignment is easy other days, in poor seeing, it wanders constantly. On the days of poor seeing I align as best I can.

Steve

[Andyb90]

35 minutes ago, RayD said:

I think that can happen with poor seeing Andy.

 

10 minutes ago, sloz1664 said:

Hi Andy,

Yep it's definitely the quality of the skies. Some days the alignment is easy other days, in poor seeing, it wanders constantly. On the days of poor seeing I align as best I can.

Steve

Its odd though as the seeing was forecast to be around 1.5 arcsec for my location in Meteoblue. I think thats pretty good isn't it? Although TBH I don't know how to get an approximate measure of the actual seeing.

Andy.

[RayD]

43 minutes ago, Andyb90 said:

 

Its odd though as the seeing was forecast to be around 1.5 arcsec for my location in Meteoblue. I think thats pretty good isn't it? Although TBH I don't know how to get an approximate measure of the actual seeing.

Andy.

Yes but it is not just the clarity Andy, it's the "turbulence" for want of a better word.  If it is particularly bad it can cause the circles to jump around like a Jack-in-the-box.  

I think if you get it mostly overlaid, you are still going to be pretty good compared to say a polar scope, as at this stage the adjustments are minute.  You can also of course do a second iteration, which once you have your first done really is very quick.

[sloz1664]

Hi Andy,

I used to be ultra finicky on my pole alignment & avidly scrutinise my phd2 graph. But, as we both have the superb Avalon mount. My phd2 graph can look like the Himalaya's but my stars are all nice, tight & round stars. 

[Andyb90]

I found a response to a polemaster issue on a QHY forum:

Before entering the precise pole adjustment, did you double click on the Polaris and rotate to match the reference stars template again? If this step is done properly, the two boxes should lock on to Polaris and the 9th magnitude reference star automatically.

The 2 boxes didn't lock on at all for me, not even to Polaris which was easily visible on screen. I think I must have done something wrong in the preceding steps. I'm just not sure what at the moment.

Andy.

[RayD]

2 hours ago, Andyb90 said:

I found a response to a polemaster issue on a QHY forum:

Before entering the precise pole adjustment, did you double click on the Polaris and rotate to match the reference stars template again? If this step is done properly, the two boxes should lock on to Polaris and the 9th magnitude reference star automatically.

The 2 boxes didn't lock on at all for me, not even to Polaris which was easily visible on screen. I think I must have done something wrong in the preceding steps. I'm just not sure what at the moment.

Andy.

Hi Andy.  I think they are referring to the step before the "start monitor" process.  You get the jumpy boxes a fair amount when there is poor seeing, so as noted by Sloz, it isn't an issue, just get it as close as you can.  For everything barring very long exposures you should be absolutely fine.

[Andyb90]

7 hours ago, sloz1664 said:

Hi Andy,

I used to be ultra finicky on my pole alignment & avidly scrutinise my phd2 graph. But, as we both have the superb Avalon mount. My phd2 graph can look like the Himalaya's but my stars are all nice, tight & round stars. 

 

3 hours ago, RayD said:

Hi Andy.  I think they are referring to the step before the "start monitor" process.  You get the jumpy boxes a fair amount when there is poor seeing, so as noted by Sloz, it isn't an issue, just get it as close as you can.  For everything barring very long exposures you should be absolutely fine.

Good points. Maybe I'm over thinking the PA a bit. My exposures are quite short, they probably won't be any longer than 5 minutes and the Esprit focal length isn't that long.

If I can get a stable target and axis I'll do the precise bit as it was so quick the first time. If not I'll stick with the rough alignment.

Andy.

 

[RichLD]

The seeing in Sheffield was terrible last night. I tend to judge the seeing by how jumpy the PM display is ?

[Andyb90]

As a quick follow up to this issue I've used the Polemaster 5 times since and reduced the exposure to 100ms. I've got a good lock on the reference stars during precise alignment and had no further issues. So looks like maybe I was just unlucky with the seeing.

Andy.

[saac]

What is supposed to happen once Start Monitor is pressed? I got to that stage the other night, I had the 2 boxes overlaid very well with little movement - I though the seeing/turbulence was good.  But all that happened was the two count indicators fluctuated a little then one settled then nothing.  I sat there monitoring the screen for about 5 minutes but nothing changed! If alignment has been successful does the software give some sort of message to say so?

Jim

[Andyb90]

17 hours ago, saac said:

What is supposed to happen once Start Monitor is pressed? I got to that stage the other night, I had the 2 boxes overlaid very well with little movement - I though the seeing/turbulence was good.  But all that happened was the two count indicators fluctuated a little then one settled then nothing.  I sat there monitoring the screen for about 5 minutes but nothing changed! If alignment has been successful does the software give some sort of message to say so?

Jim

When the red/green targets/circles are aligned the polar alignment should be complete. Although you can do further alignments if you want for checking. I usually just do it once.

Andy.

[saac]

Andy,

Thanks for that. That's what I had been doing and what I thought was all that had to be done. However the other day for some reason I started to think because it says "Start Monitoring" I thought that there must be an end to the process with some sign to say it had ended.  Anyway, thanks for confirming that.

Jim