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kens

New PHD2 tool for static polar alignment

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kens    135

Thanks for the feedback. I was expecting it to be more difficult in the NH. Next time if you can get a screen shot showing the StaticPA window and the main phd2 display I can see if there is a reason for the misalignment and fix it.

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kens    135

I just submitted a set of changes including a bug fix. In some situations the code was calculating a negative distance from the pole which affected the display of corrections. Should be available in the next dev release.

Tonight I was able to do some extensive testing at different focal lengths and a range of distances from the pole and the issue no longer appears, in the southern hemisphere at least.

Attached example is at 70mm focal length. Initially the camera was aligned several degrees away from the main OTA and the offset was clearly indicated on the display. A few slews in declination got the camera FOV aligned to where the mount was pointing. The FOV is about 3 deg x 2 deg.

You can see some of the cosmetic changes I've made. The circles showing where th various reference stars belong are larger and are now labelled. The lines a dimmer so they do not hide the stars.You can also see that most stars are very close to their circles. I had chosen star C from the list but the one I selected on the display is anoher star not on the list. The true star C is just outside its circle.

SPA-DBK.thumb.png.536097ef8f11e8229a4098ac63ee7df5.png

 

Edited by kens
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Atreta    365

This is a feature i've much wanted to see in phd2.  Yours specially since i live in the southern hemisphere and it looks optmal for it. 

Gonna download and give it a go when the clouds break. 

Thanks a lot. 

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kens    135

In dev3 you can double click on the helper display to centre that point and thereby pan around. e.g if you double click on Polaris it will centre it. 

There's also a couple of bugs I've just submited fixes for: one is inversion of the image caused by (lack of) a side of pier adjustment and the other is an obscure bug affecting manual mode.

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spillage    287

@kens

Cheers for the update Ken. That works a treat, after trying last time and failing I ran the drift alignment and before I shut down tonight I quickly ran this again. I would say it looks good and shows my drift alignment is slightly out!! Not sure what happened to the screen capture but was done through teamviewer.

 

 

phd2_Dev3.jpg

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kens    135

Thanks for the feedback and I'm very glad it works for you. For now I would still regard drift alignment as the more accurate method . But if the two give similar results I think you cn be pretty sure you have a good alignment. The main thing to watch for is whether you get the central point consistently in the same place as that is the calculation most subject to the vagaries of the mount and conditions; and everything else rides on that.  With these latest changes I am feeling more confident that it will work for most people in the northern hemisphere

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GuLinux    146

Hi,

Quick feedback from me:

The interface needs some refinements, but you're on the right track :)

I tried using this with an ASI 178mm, and a 25mm lens.

I know it's quite a short focal length, but it's more or less what the PoleMaster uses, so I'd say it might be worth implement support for such wide field of view.

Right now, there's no way to zoom in, I've tried to do the polar alignment procedure anyway, but the app crashed on the third rotation.

 

Still, I know it's kinda of an edge case :)

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kens    135
5 hours ago, GuLinux said:

Hi,

Quick feedback from me:

The interface needs some refinements, but you're on the right track :)

I tried using this with an ASI 178mm, and a 25mm lens.

I know it's quite a short focal length, but it's more or less what the PoleMaster uses, so I'd say it might be worth implement support for such wide field of view.

Right now, there's no way to zoom in, I've tried to do the polar alignment procedure anyway, but the app crashed on the third rotation.

 

Still, I know it's kinda of an edge case :)

Are you using dev3? If so can you send me the debug log so I can see the cause of the crash. The error handling in that version was improved over the earlier release so if its crashing there's something I missed. Most likely the short focal length means a much bigger rotation is needed so it could be you did not rotate the mount far enough for the algorithm to detect an arc. 

dev3 also provides the ability to pan the helper display and rotate it to match the view with a manual mount. Where did you want to be able to zoom in? Is that the help display or the main display? The helper display should match the FOV you see on the main display so zooming does not make sense there. On the main display it might be nice to zoom in on the corrections needed but I'll need to see if that's possible without impacting the guiding algorithm. But in the main, if you need to zoom in, why use a 25mm guide scope? :) 

dev4 should be out soon - it has some bug fixes that affect the helper display.

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GuLinux    146

Hi,

No, it was dev2, unfortunately I haven't had more time after that.

I'll try with a bigger rotation then :)

Anyway, it's not a guide scope, that's the point!

I'm trying to do something quite similar to the polemaster

IMG_20171012_223654.thumb.jpg.2801e87b2e3e82112274a2449edcf2fc.jpg

Edited by GuLinux

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kens    135

 

You'll see some nice new features in dev4 that help both manual and auto users:

  • The JNOW algorithm will hopefully result in more accurate placement of the reference stars based on their J2000.0 coordinates which in turn should make the corrective moves more accurate
  • You have the option to turn off the reference star orbits to make the corrections easier to see
  • Auto mode users can now adjust the rotation (hour angle)  of the reference stars. It is meant for small adjustments but the full 360 degrees is available. The idea behind this is that you adjust the rotation so that the corrections to move, say, three reference stars to their correct positions is the same for all three. That provides greater accuracy as it accounts for any pointing error in the mount.
  • The calculated PA error in arc minutes is now displayed on the status line for bragging rights and for comparison with drift alignment. In truth, it should be used so you know when you are "near enough"
  • Slightly brighter colors for alt and az corrections should hopefully make it easier to see them in the dark
  • A "Clear" button is provided to clear the display completely so you don't need to close and reopen the tool
  • A "Flip Camera" option is provided for those situations where the displayed star positions are inverted from their true positions. Other changes in the code hopefully make this redundant but for now its worth having
 

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