PHD2

[Manuka]

Hi everyone, 

I'm using for the first time PHD2 and after connecting my mount and guide camera (Star Adventurer pro + ZWO 30mm f/4 + Orion Starshoot autoguider), the calibration process fails all the time. I've watched Peter Zelinka's tutorial, but in the end, after 60 west steps, I always get the same "the star didn't move enough" message. 

Why does phd2 wants the star to move anyway? isn't having stars as still as possible the purpose of guiding?🤯

I must obviously be too much of a dummy to be able to use a program called Press Here Dummy 😅😤

[alacant]

Hi

Start with this.

If you want a specific answer to why your calibration fails, you need to upload your log files. This is also covered by the link.

Cheers

[michael8554]

PHD2 gives up trying to Calibrate after 60 steps if insufficient movement has been measured.

1. Perhaps it's as simple as you are asking PHD2 to Calibrate Dec ?

The Star Adventurer doesn't have a Dec Drive, so you should deselect Dec guiding before Calibrating.

2. You have a ZWO 30mm f/4 guidescope.

What focal length did you enter in the PHD2 Equipment Profile wizard ?

30mm is the aperture, but the focal length is f/4 x 30mm = 120mm.

That's explained at 14:40 in the video you looked at.

3. If you have 120mm entered, then perhaps the Guide Rate is too low.

If the Star Adventurer doesn't have a way of setting the guide Rate, experiment with the size of the PHD2 Calibration Step.  Cal should take about 12 steps

Try doubling to start with and see how many steps Cal took.

Videos are only good if the author knows what they're talking about.

Best to read the PHD2 Instructions in the Help menu.

And post the GuideLog.

Michael

 

 

[Manuka]

Hi everyone, once again I'm trying to autoguide and still failing to calibrate (RA only). 

Here's the guide log and the debug log.

Thanks for your help

PHD2_GuideLog_2022-02-24_231644.txt

PHD2_DebugLog_2022-02-24_231644.txt

[alacant]

2 hours ago, Manuka said:

still failing to calibrate

Hi

Select a star before attempting to calibrate? Tools -> autoselect star

Then hit the guide button. 

HTH
23:17:45.880 03.006 6520 Exposure complete
23:17:45.917 00.037 6520 worker thread done servicing request
23:17:45.917 00.000 5908 OnExposeComplete: enter
23:17:45.917 00.000 5908 UpdateGuideState(): m_state=1
23:17:45.917 00.000 5908 UpdateCurrentPosition: no star selected
23:17:45.917 00.000 5908 Throw from C:\cygwin\home\agalasso\projects\phd2\guider.cpp:1345->unable to update current position
23:17:45.917 00.000 5908 Status Line: No star selected

Edited February 24, 2022 by alacant

[michael8554]

The mount is moving and incrementing in a roughly linear fashion.

But it's failing to move enough after 60 steps.

The PHD2 Calibration Step is 750ms.

So as I have already suggested, keep increasing the size of the Calibration Step until Calibration takes about 12 steps.

Try 2000ms to start with.

Your Guiding Image Scale is    Pixel scale = 8.94 arc-sec/px,

Which is too high, and is contributing to your Cal problems.

Due to the large pixels     pixel size = 5.2 um, and the very short guidescope   FL Focal length = 120 mm

You need either a 3.75um pixel guidecam, or a f/4 50mm or f/4 60mm guidescope.

Michael

[Manuka]

Sorry guys I really struggle to understand this;

I've increased calibration step even up to 15000ms (not sure what this is supposed to do) but I still get the same error after the same amount of steps (61).

53 minutes ago, michael8554 said:

Your Guiding Image Scale is    Pixel scale = 8.94 arc-sec/px,

Which is too high, and is contributing to your Cal problems.

Due to the large pixels     pixel size = 5.2 um, and the very short guidescope   FL Focal length = 120 mm

You need either a 3.75um pixel guidecam, or a f/4 50mm or f/4 60mm guidescope.

Does this mean I can't auto-guide with the equipment I've got and I need to change it?

Thanks again for your patience,

 

Luca

[michael8554]

1 hour ago, Manuka said:

I've increased calibration step even up to 15000ms

Not according to the GuideLog.

Both Cals were at 750ms.

Post the Log where you tried 15000ms.

Michael

Edited February 24, 2022 by michael8554

[AstroMuni]

2 hours ago, Manuka said:

Sorry guys I really struggle to understand this;

First and foremost select a guide star as suggested by @alacant, increase cal step to 2000 as per @michael8554. Give it a shot and then post logs here. Good luck

[kens]

Also tell us where your scope was pointing when you di the calibration. If it was in the home position pointing near the pole then you wont get enough movement in RA for the calibration to work.

You should also try the manual guiding tool to check that the mount is actually responding to guide commands. To do this, point near the celestial equator and select a star. Then choose the Manual Guide option on the Tools menu. Use the maximum pulse duration (5000 ms) and click the west button. You should see the star move steadily on the screen for 5 seconds. Click East and you should see it move the other way for 5 seconds.

[Manuka]

Here's the log of all my different attempts last night. I did not go to 15000ms (I thought I did).

 

8 hours ago, kens said:

Also tell us where your scope was pointing when you di the calibration. If it was in the home position pointing near the pole then you wont get enough movement in RA for the calibration to work.

I was pointing at Rosette Nebula. At that time of the night it was about 30 degrees ALT and about +312 degrees AZ

PHD2_GuideLog_2022-02-24_231644.txt PHD2_DebugLog_2022-02-24_231644.txt

[michael8554]

The latest 24th Feb GuideLog has more data than the previous 24th Feb log, including those attempted Cals at Cal steps up to 10,000.

But although they definitely moved RA, they failed to move RA enough.

With 2000ms step it moved about 8arcsecs (or pixels, I'm not sure what the scale reports) :

 

 

With 10000 step it still only moved a max of about 8arcsecs, so there's no correlation between moves and Step Size:

 

 

In between the two Cals above there was this third one at 750ms.

Why has the RA direction moved 90 degrees ?

Was there a flip after the first Cal, then a flip back ?

Or is the guidescope or guidecam loose and rotating  ?

 

I'm not familiar with the Star Adventurer, but perhaps it's not in the correct mode for guiding.

You could check the ST-4 cable isn't faulty.

Michael

 

[Manuka]

Thanks for your help guys, the culprit might be the st4 cable. I'm using a random one I've found in the house without knowing that they aren't all the same. I've purchased a guiding compatible one, will update the thread once it'll arrive🤞.

Luca