22 replies to this topic

[CalifDan]

I am still learning how to assemble sequences in NINA and making some progress.  My process, prior to running the sequence, is to polar align, slew somewhere near the meridian and equatorial arc and run auto focus, then start guiding with PHD2 and run Calibration.  Once complete I let it guide for 10-15 minutes to make sure everything appears to be working.  Then I stop guiding and Park the telescope.  Then I run the sequence which because I have limited night sky, usually includes a wait for time instruction before starting.

 

This has worked well with a single target.  Once the Sequence fires, it goes to the target, runs the instructions, ends up with Parking again.  Guiding is good, sometimes excellent.

 

Several nights ago, I tried doing two targets in one sequence.  The first night, it was a direct slew from one target to the other once imaging was done on the first.  I did stop guiding prior to the slew, captured, did an autofocus and then commanded the guiding back on.  The guiding on the second target did not work.  I had to interrupt the sequence, manually invoke a recalibration, and then it worked.  I thought maybe it was an anomaly.

 

Last night I set up two targets again.  This time, I parked the scope between targets for about two hours and used a wait until time command to bring it out of park and start the process on the second target.  Again, the guiding failed.  I paused the sequence, called the calibration routine and then restarted the sequence and all was fine.

 

I was under the impression that once polar aligned correctly and with PHD2 calibrated, it should run successfully.  Particularly if the targets are both on the same side of the meridian, and these both were on both nights.  In fact, I thought I read you could reuse an existing calibration.  I have limited experience with a Meridian Flip as most of my visible sky is west of the meridian.  However, I have done a few and guiding has worked well from a single calibration on both sides of the meridian.

 

I think I can solve this within the Sequence by "forcing" a recalibration prior to the second target.  I will try that tonight.  But I am interested in understanding the limitations of the initial calibration to subsequent targets in the same sequence and what behavior I need to accommodate within a sequence.

 

This is an IOptron GEM 28 and is not overloaded.  Most nights I get what I think are exceptional guiding.  I am Bortle 5.  Once calibrated, I normally see guiding numbers of ASC (.08 to .14) and DEC (.08 to .12) and total of .14 - .18.  Stars are round and on a good seeing night, autofocus might not fire for long periods.  In both instances, the initial target was fairly high in the sky and the second target was near the meridian and DEC about -15.

[DirtyRod]

You don’t need to recalibrate between targets. Once your mount is polar aligned and calibrated, you don’t need to redo those again until you move your mount or change your imaging train. I do multiple target in N.I.N.A. all the time so I’d look at your sequence. After you slew to the second target you need to start guiding. I assume that command is missing from your sequence.

[CalifDan]

Well, it isn't missing.  The commands are Unpark, Slew-Center-Rotate, Select Filter, Auto-Focus and Start Guiding.  At that point, the graph is all over the place.  This is the same set of sequence commands I'm giving for the first target and that works just fine.

 

As I indicated, if I pause the sequence, run calibration, restart he sequence, it is fine.  I would expect it to work as you have indicated.

[DirtyRod]

Interesting. If PHD2 cannot lock onto and keep a guide star then it will stop guiding. I’d check both the N.I.N.A. and PHD2 logs. There should be an error message that indicates what is going on. 
 

Sounds like you have all the right commands. Are you restarting the entire sequence from the beginning or resuming it from where you left off? I don’t know how your sequence is organized so restart sounds like it’s going back to step 1 versus continuing at the step after the first target. 

[CalifDan]

I will have to see if I can find anything in the logs.  I am not restarting the script.  I hit the pause and then manually select calibration in PHD2 and once it is done, continue the sequence from where it was.

[rgsalinger]

I am still learning how to assemble sequences in NINA and making some progress.  My process, prior to running the sequence, is to polar align, slew somewhere near the meridian and equatorial arc and run auto focus, then start guiding with PHD2 and run Calibration.  Once complete I let it guide for 10-15 minutes to make sure everything appears to be working.  Then I stop guiding and Park the telescope.  Then I run the sequence which because I have limited night sky, usually includes a wait for time instruction before starting.

 

This has worked well with a single target.  Once the Sequence fires, it goes to the target, runs the instructions, ends up with Parking again.  Guiding is good, sometimes excellent.

 

Several nights ago, I tried doing two targets in one sequence.  The first night, it was a direct slew from one target to the other once imaging was done on the first.  I did stop guiding prior to the slew, captured, did an autofocus and then commanded the guiding back on.  The guiding on the second target did not work.  I had to interrupt the sequence, manually invoke a recalibration, and then it worked.  I thought maybe it was an anomaly.

 

Last night I set up two targets again.  This time, I parked the scope between targets for about two hours and used a wait until time command to bring it out of park and start the process on the second target.  Again, the guiding failed.  I paused the sequence, called the calibration routine and then restarted the sequence and all was fine.

 

I was under the impression that once polar aligned correctly and with PHD2 calibrated, it should run successfully.  Particularly if the targets are both on the same side of the meridian, and these both were on both nights.  In fact, I thought I read you could reuse an existing calibration.  I have limited experience with a Meridian Flip as most of my visible sky is west of the meridian.  However, I have done a few and guiding has worked well from a single calibration on both sides of the meridian.

 

I think I can solve this within the Sequence by "forcing" a recalibration prior to the second target.  I will try that tonight.  But I am interested in understanding the limitations of the initial calibration to subsequent targets in the same sequence and what behavior I need to accommodate within a sequence.

 

This is an IOptron GEM 28 and is not overloaded.  Most nights I get what I think are exceptional guiding.  I am Bortle 5.  Once calibrated, I normally see guiding numbers of ASC (.08 to .14) and DEC (.08 to .12) and total of .14 - .18.  Stars are round and on a good seeing night, autofocus might not fire for long periods.  In both instances, the initial target was fairly high in the sky and the second target was near the meridian and DEC about -15.

There's a setting in the PHD brain to tell it to use the same calibration data -- Auto Restore Calibration. Maybe this needs to be checked. I have all of my rigs with it checked. I think that if it's not checked you're in for some kind of problem.  

[CalifDan]

Checked.  I do have Auto Restore Calibration checked.

[rgsalinger]

I use the same calibration for months on end with targets everywhere and automated flips. Please post a log so I can have a look at what's happening. Is the guiding rotten or actually running away? Some mounts need to have DEC corrections reversed and some do it in the ASCOM driver after a flip automatically. If it's running away that might be the issue. 

[CalifDan]

The log is attached.  Rather long.

 

Starts out at 21:38 and I started guiding.  Shortly after I ran the calibration at 21:38.  Shortly after, I parked the scope.

 

The first session guiding begins at 21:41 and that runs fine.  Ends at 23:44.  I parked the telescope.

 

At 02:05 the next guiding starts and that is when it gets out of control.  I stop it at 02:06 (paused the sequence) and start a calibration.

After, I restarted the sequence, and it worked.

 

I appreciate anyone looking at the log.  I'm not yet qualified to extract much from the same.

Attached Files

•  PHD2_GuideLog_2025-06-16_165645.txt   454.25KB   5 downloads

[rgsalinger]

Your guiding is running away because you have the wrong "reverse DEC corrections" setting. If your guiding worked in the past, it's a good bet that somehow it got changed. I blame these sorts of things on my cat. 

[michael8554]

Hi Dan

 

For both sessions PHD2 reported "Pier side = East,"

 

But as Ross said, if you have the wrong "reverse DEC corrections" setting,  then a Cal will be required.

[CalifDan]

I suspect I need a little help with this one.

 

I have assumed that Pier Side = East to mean that when shooting or calibrating the weighted end was on the west side and the telescope end was on the east side of the tripod setup. Maybe that is incorrect.  If it is a reference to pointing direction, then I probably have that reversed.

 

In advanced settings, I have "Reverse Dec output after meridian flip" unchecked.  Is that the "reverse Dec corrections" setting that you are referencing?  If so, should it be checked?  The pop-up instructions say to do so if your mount needs it.  Since I was not having a tracking problem before or after a meridian flip, I assumed unchecked was correct.

[AstroFromHome]

Are you using the legacy Sequencer or the normal Sequencer in NINA?

 

Could you please Post your settings for both targets?

In the legacy Sequencer it is not so obviously that you need to set the guiding slider for the second target also to "on".

In the full Sequencer as it works it is more obviously that the command "Start Guiding" needs to be included for each of the targets in the sequence.

[CalifDan]

I am using the normal Sequencer.  I have taken a page shot of the first and second targets.  NGC 4565 is the first target and the second is M16.  Notice the park and wait time between the two.  Start guiding is included in each target instruction.  Appreciate the help.

 

I did the same run last night.  This time, I changed the second target start guiding to include forced calibration.  It did the calibration and I got the first five 5-minute images no problem.  Then it ran away again.  As I did the night before, the beeping woke me up, I paused the sequence, ran calibration, restarted guiding and the sequence and it finished out the sequence with no problems.

 

There is something I am missing somewhere.

Attached Thumbnails

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[rgsalinger]

Pier side east means that the scope is pointing west. check the setting I suggested and that might just fix the issue. It's easy to uncheck things inadvertently

[CalifDan]

Pier side east means that the scope is pointing west. check the setting I suggested and that might just fix the issue. It's easy to uncheck things inadvertently

I don't know what setting you are referencing.  In PHD2?  In NINA?  I don't see a setting that specifically is called "reverse Dec corrections".  I responded above to your suggestion asking for specifics.

[rgsalinger]

"Reverse DEC Output after Meridian Flip" on the Guiding Tab, lower left. 

[CalifDan]

Thanks for that response.  That box was unchecked, but is now checked.  I had left it unchecked intentionally as it wasn't clear to me if the mount required it and previous meridian flips didn't provide a problem with guiding.  It is possible that it was checked prior and the cat unchecked it.

 

That said, I don't understand the significance of that check-box in relation to my problem.  I had no targets east of the meridian, hence there was no meridian flip.  I did the initial guiding calibration on a target west of the meridian.  Calibration and both targets were west of the meridian when the problem occurred on both nights.  Unless parking the scope between the two targets is somehow messing things up?

 

I appreciate all and any help.  My goal is to understand why I'm making choices in the software to achieve the results I want.

[AstroFromHome]

You're welcome.

This checkbox to reverse Dec is required for some mounts for others you are in the need to keep it turned off.

 

If you see that PHD2 is moving out of position more and more and PHD2 is trying to correct more and more in that direction this option needs to be set to the other setting.

Some mounts realize that you are imaging on the other side of the Meridian either by flip or new target. Others don't do that. Generally speaking neither behaviour is better than the other.

 

I would give it a try.

 

Thanks for the screenshots of you sequence. It looks pretty good what you have in. Just from personal preference and having a limited view from my balcony I like use the "loop until" or how it is called for the imaging instruction. That ensures in my situation not to image my neighbors wall for 30 minutes in the middle of the night. 

[Juno18]

Hi Folks,

I could be off base here, but I thought the same thing when Ross mentioned  "Reverse DEC Output after Meridian Flip". I have been bitten by that before.

 

The OP said that he calibrated and ran both imaging sessions on the same side of the meridian. So, the same calibration should have applied regardless of the "Reverse DEC Output after Meridian Flip" selection since there was no flip involved?

 

I see in the guide log that log 2 shows the original calibration (calibration looks good). Guiding in log 3 and 4 was okay. The scope was parked at 2158, then restarted slewing at 0203. The scope was pointed to the same side of the meridian as the original calibration (log 2), so the calibration in log 2 should have still applied. No flip, no reverse needed. When guiding started in the 0203 and also in the 0205 log, I am no expert, but I see guiding corrections issued by PHD2, but absolutely no mount response for either DEC or RA which both were running pretty wild.

 

Were there error messages generated? To me it looks like neither DEC or RA axis were responding.

 

I see in earlier posts if the question was asked if the Auto Restore Calibration box was checked in the Guiding tab and the OP confirmed that. 

 

I have had weird issues in PHD2 that were corrected by creating a new profile using the wizard. Has this been tried?

 

If the Auto Restore Calibration box was checked and the mount and the mount was not guiding correctly on the second target (following a guiding stop and mount park on the first target), and I tried a new profile, I would definitely get on the PHD2 Guiding Forum https://groups.googl...pen-phd-guiding.

These are the folks that wrote the software and they are tremendously helpful.

Follow their instructions how to upload a guide  log at

https://openphdguiding.org/getting-help/.

Edited by Juno18, 19 June 2025 - 02:22 PM.

[CalifDan]

Thanks.  I have not tried loading a new profile and will give that a try.  The behavior you describe (commands and no response) is what it looked like.  On the graph, the diversion of the RA and DEC lines was significant (about 45 degrees.  Since the mount was polar aligned, I would not expect an unguided (lack of guiding response) to be that significant.  Unless the mount just stopped tracking completely for those seconds.

 

I ran the same sequence last night and it ran from start to finish with no issues.  Go Figure!  Since you noticed a non-response from the mount, I'm wondering if it could be as simple as a marginal connection.  I run NINA off a Mini PC mounted on the tripod.  The mount is fed from the Mini PC through the handset.

 

I appreciate the link over to the PHD2 forum.  Posing the problem there makes a lot of sense and I do want to understand the nuances of guiding.  I'm using a 480 mm scope right now, and the Ioptron Gem 28 seems adequate for the weight and guides well enough.  I want to get something in the 1200-1800 mm range at some point and I'm not sure the Gem28 will be up to that.

 

I will try to circle back to this and post any resolution.

[CalifDan]

I promised to come back and close this out.  The advice to post on the PHD2 forum was spot on.

 

The problem was that I had set up PHD2 to recognize a Rotator.  I believe that occurred some months ago when I was using an OAG.  Somewhere near the time I put the rotator on the image train, I removed the OAG and went to a separate guide scope.  It did not occur to me that I should not reference the rotator within the PHD2 configuration, although it makes perfect sense.  The reason I had no problem with PHD2 in the intervening time is because I did not use the rotator.  I was too busy learning how to use everything else and left learning how to integrate the rotator for later.  Later was a few nights ago when I had two targets and changed the rotation between the targets.  PHD2 did not like that.

 

The problem should now be solved and hopefully, this thread will help someone else avoid a similar issue.

[Juno18]

Excellent news! 
 

I went to the PHD guiding forum and read Bruce’s response.

Looks like you are in good shape now.

 

A new profile would have probably worked too. 
Several years ago, I had an issue with my target in Nina getting off center over time. That was before I was using the Center after drift instruction in the sequence. I posted to Nina’s discord and they told me to delete the PHD profile and create a new one from scratch. That took care of that issue.

Edited by Juno18, 20 June 2025 - 09:59 AM.