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Long wait time for auto guider settling in SGP

Beginner Astrophotography Software
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#1 erpagris

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Posted 20 September 2021 - 08:22 PM

I am relatively new to SGP and PHD2. I have done a lot of reading, searching and youtubing to get to the bottom of this, and I think it is a calibration problem. When running a sequence, I am getting a long wait time after each image, even when not dithering. Last night it took over 20 minutes to capture three 90 second images. Most of the time I was waiting for SGP to settle. My guiding RMS was between .30 and .40 at the time. I was imaging the Wizard nebula, near the meridian. Seeing conditions were ok, with a full moon and occasional light clouds, but I never lost guiding. I had the auto guide settings in SGP set to High Dither, every 5 frames, Settle at 0.3 pixels for 5 seconds. I am using a 190mm guidescope and an ASI 120mm mini cam. My mount is a Losmandy GM811G and my scope is an Explore Scientific ED102CF. I am pretty sure that I need to change the Settle at to a larger pixel size, but not sure how high to go. I have read quite a few forum posts on the subject, but do not understand a lot of it. I don't want to just keep plugging numbers in and see what happens, as we don't have very many clear nights and winter is coming.

 

I have the latest version of PHD2 and SGP is at 320613

 

Thanks for reading.

 

Eric



#2 jsmithsd

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Posted 20 September 2021 - 08:34 PM

Settling at 0.3 pixels may be to aggressive. Compute your pixel resolution on the sky and then set for whole pixels that are inside the seeing. I recommend 2-3 pixels as a start.


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#3 erpagris

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Posted 20 September 2021 - 08:38 PM

Thank you for your advice. I do not know what "Compute your pixel resolution on the sky and then set for whole pixels that are inside the seeing." means. Can you please explain a little?



#4 KNak

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Posted 21 September 2021 - 07:53 AM

I have mine set to 2", which at your guide camera image scale of 4"/pixel, that would calculate to 0.5 pixels.  But if you are taking 3 consecutive images, SGP should only settle once at the beginning of the sequence since guiding should not pause between consecutive frames (and you are only dithering every 5th frame). In SGP autoguiding options, do you have the "Restart current frame when" box enabled, and if so what do you have this set to (in pixels)?


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#5 erpagris

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Posted 21 September 2021 - 08:18 AM

I have mine set to 2", which at your guide camera image scale of 4"/pixel, that would calculate to 0.5 pixels.  But if you are taking 3 consecutive images, SGP should only settle once at the beginning of the sequence since guiding should not pause between consecutive frames (and you are only dithering every 5th frame). In SGP autoguiding options, do you have the "Restart current frame when" box enabled, and if so what do you have this set to (in pixels)?

"SGP should only settle once at the beginning of the sequence since guiding should not pause between consecutive frames (and you are only dithering every 5th frame)."

 

SGP is actually pausing to settle after each frame. With a very long wait time. I will try increasing the settle to 2 pixels and see how it reacts. Looks like clouds every night for the next week or so. It may be a while.

 

I do not have the "Restart current frame when" box enabled. Should I? If so, what should I set it to?

 

Thank you.



#6 KNak

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Posted 21 September 2021 - 08:45 AM

According to the SGP documentation, settling is only active either after dithering, or an autofocus run.  So if you are not dithering or autofocusing every frame, I'm not sure why its settling every frame.  You can try 2 pixels to check that you're tweaking the right thing, but that's a large value IMO (equivalent to 8") as a permanent setting and is about the same as turning the feature off (i.e. your mount will almost always track much better than that over 5s).

 

Its up to you whether to use the restart current frame feature.  I do, and set it to about 2x my typical guiding RMS.  But I would ignore that for now (leave unchecked) until you get the settling issue figured out.


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#7 erpagris

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Posted 21 September 2021 - 11:09 AM

According to the SGP documentation, settling is only active either after dithering, or an autofocus run.  So if you are not dithering or autofocusing every frame, I'm not sure why its settling every frame.  You can try 2 pixels to check that you're tweaking the right thing, but that's a large value IMO (equivalent to 8") as a permanent setting and is about the same as turning the feature off (i.e. your mount will almost always track much better than that over 5s).

 

Its up to you whether to use the restart current frame feature.  I do, and set it to about 2x my typical guiding RMS.  But I would ignore that for now (leave unchecked) until you get the settling issue figured out.

It is waiting for guider to report that it is done settling after every capture, without autofocus or dithering.

 

I think that, since we have a cloudy/rainy stretch coming for the next week or so, I am going to create new equipment profiles in SGP and PHD2, raise the settling time a little bit at a time, and go from there when the skies clear again. Maybe starting with fresh profiles will help.

 

I am going to try setting it up using suggestions from here: https://www.cloudyni...-done-settling/

 

Thank you



#8 StephenW

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Posted 21 September 2021 - 11:49 AM

If you upload your SGP and PHD2 logs we'll be able to see what is triggering the settling



#9 erpagris

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Posted 21 September 2021 - 12:55 PM

here is the PHD2 guide log

Attached Files



#10 erpagris

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Posted 21 September 2021 - 12:56 PM

The SGP log is too big to upload. So I split it in 2 and zipped it. Hopefully this works.

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#11 erpagris

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Posted 21 September 2021 - 12:58 PM

If you upload your SGP and PHD2 logs we'll be able to see what is triggering the settling

Here is part 2 of the SGP log. Thank you for looking.

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#12 StephenW

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Posted 21 September 2021 - 01:11 PM

>It is waiting for guider to report that it is done settling after every capture, without autofocus or dithering.

 

From your PHD2 logs, dithering is enabled and settling is taking a very long time, most likely because yo have the settling constraints set too tightly (e.g. "settle within 1 pixel for X seconds").  If loosen the settling constraints (increase the pixel parameter and reduce the duration parameter), then it should settle more quickly.

 

Or if you really don't want any dithering between frames, turn that off in SGP.



#13 erpagris

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Posted 21 September 2021 - 03:14 PM

>It is waiting for guider to report that it is done settling after every capture, without autofocus or dithering.

 

From your PHD2 logs, dithering is enabled and settling is taking a very long time, most likely because yo have the settling constraints set too tightly (e.g. "settle within 1 pixel for X seconds").  If loosen the settling constraints (increase the pixel parameter and reduce the duration parameter), then it should settle more quickly.

 

Or if you really don't want any dithering between frames, turn that off in SGP.

Thank you, I will give that a try.




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