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PHD2 calibration isn't working, unable to figure out why.

Astrophotography Beginner Software
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#1 jackdaniels3773

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Posted 23 May 2022 - 11:18 AM

I recently started this hobby and am very much in the learning phase right now so hopefully this is just an example of something very simple I've missed.  I started off the first couple of nights doing polar alignment through the mount scope, that was tedious to say the least but it worked, and then a 3 star alignment with the hand controller and it worked quiet well.  Since then, I've upgraded to using the hand controller in PC direct mode and connecting everything to APT, Stellarium, EQMOD, etc etc and slowly learning as I go.  I've consumed dozens of hours of youtube video from a wide array of fantastic members of this community and really appreciate how much support is out there.  

That said.....

I'm coming up empty on everything I've searched so far to get guiding in PHD2 working with my guide scope/camera and my results just don't make much sense to me.

Current setup: 

Orion EQ-G mount
William Optics GT81 with 6AIII .8x reducer

Canon Rebel DLSR 

WO Uniscope 50mm guide scope w/ ZWO ASI290MM mini

I can successfully connect everything and navigate the sky from Stellarium with a fair amount of accuracy and Sharpcap has made polar alignment so much easier.  But getting PHD2 to guide and finish calibration successfully has failed at every step.  I went through the setup wizard for the ASI camera and let it build a dark library and also spend an embarrassingly long time making sure the scope was in focus.  Now when I start calibration, I have tracking started in APT, I can take 20 - 30 subs that are sharp and in focus so I know guiding is working, but calibration will fail 99% of the time and the 1 or 2 times it succeeded, it lost the star almost immediately afterward.  In addition, the calibration graph just looks weird.  I'm not sure how to chase this down but would appreciate any thoughts or ideas from the community on what I'm sure is just user error.

 

 

Attached Thumbnails

  • 5-22-calibration.png

Edited by jackdaniels3773, 23 May 2022 - 11:19 AM.


#2 rgsalinger

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Posted 23 May 2022 - 11:30 AM

If you are using EQMOD, check in the GUI to make sure that you have set BOTH guide rates to .5x sidereal. It looks to me as if one of them might be zero. That would be the first step. You cannot guide until you get a good calibration. I've always used the shoestring cable rather than PC direct, so I can't advise you on how to make that work but again, you can't guide without a good calibration. 

 

You should post some screenshots showing your settings in EQMOD or whatever you are using to control the mount (ASCOM driver?). Finally, have you installed the ASCOM platform on the system. My guess is that you have but if you haven't that explains the situation as well. 

 

Rgrds-Ross


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#3 jackdaniels3773

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Posted 23 May 2022 - 11:36 AM

I do have the ASCOM platform installed and have experimented both ways of connecting it, I just ended up going with the PC direct mode on the hand controller which so far has seemed to work.  I'm willing to be schooled on that and corrected though if there's a better way.  I followed a couple of guides and videos that talked through the settings to change in EQMOD to enable pulse guiding and thought I got all of them.

Attached Thumbnails

  • 5-22-calibration-2.png

Edited by jackdaniels3773, 23 May 2022 - 11:40 AM.


#4 OregonAstronomer

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Posted 23 May 2022 - 11:44 AM

You've probably checked these already, but if not, click on the Brain icon in the main window to bring up Advanced Settings. On the Guiding tab, make sure that "Enable mount guide output" is checked. On the Algorithms tab, make sure "Dec guide mode" is set to Auto.

 

Arnie



#5 rgsalinger

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Posted 23 May 2022 - 11:54 AM

EQMOD settings look good. Something is amiss in PHD, I would think.

Rgrds-Ross



#6 bobzeq25

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Posted 23 May 2022 - 11:55 AM

I recently started this hobby and am very much in the learning phase right now so hopefully this is just an example of something very simple I've missed.  I started off the first couple of nights doing polar alignment through the mount scope, that was tedious to say the least but it worked, and then a 3 star alignment with the hand controller and it worked quiet well.  Since then, I've upgraded to using the hand controller in PC direct mode and connecting everything to APT, Stellarium, EQMOD, etc etc and slowly learning as I go.  I've consumed dozens of hours of youtube video from a wide array of fantastic members of this community and really appreciate how much support is out there.  

That said.....

I'm coming up empty on everything I've searched so far to get guiding in PHD2 working with my guide scope/camera and my results just don't make much sense to me.

Current setup: 

Orion EQ-G mount
William Optics GT81 with 6AIII .8x reducer

Canon Rebel DLSR 

WO Uniscope 50mm guide scope w/ ZWO ASI290MM mini

I can successfully connect everything and navigate the sky from Stellarium with a fair amount of accuracy and Sharpcap has made polar alignment so much easier.  But getting PHD2 to guide and finish calibration successfully has failed at every step.  I went through the setup wizard for the ASI camera and let it build a dark library and also spend an embarrassingly long time making sure the scope was in focus.  Now when I start calibration, I have tracking started in APT, I can take 20 - 30 subs that are sharp and in focus so I know guiding is working, but calibration will fail 99% of the time and the 1 or 2 times it succeeded, it lost the star almost immediately afterward.  In addition, the calibration graph just looks weird.  I'm not sure how to chase this down but would appreciate any thoughts or ideas from the community on what I'm sure is just user error.

This is not something subtle.

 

Your DEC is not responding to PhD2, at all.

 

Using PhD2 "native" rather than embedded in another program may help you sort this out.  The imaging suites are great, once you have things working well.  But they're black boxes that make it harder to diagnose issues.


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#7 jackdaniels3773

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Posted 23 May 2022 - 12:12 PM

You've probably checked these already, but if not, click on the Brain icon in the main window to bring up Advanced Settings. On the Guiding tab, make sure that "Enable mount guide output" is checked. On the Algorithms tab, make sure "Dec guide mode" is set to Auto.

 

Arnie

Thanks for the suggestion, I did check those and they are both set to those options already.

 

This is not something subtle.

 

Your DEC is not responding to PhD2, at all.

 

Using PhD2 "native" rather than embedded in another program may help you sort this out.  The imaging suites are great, once you have things working well.  But they're black boxes that make it harder to diagnose issues.

So far I have been using PHD2 natively and not through APT up until last night as I was trying to invoke it another way to see if it would respond any better.  I know for sure the mount is working just fine because if I shut everything down and just go back to the hand controller, I can already take decent pictures but I'd really like the guide scope to be working so I can get sharper images with longer exposures.  I'm completely confused as to what is configured incorrectly. 

 

Really appreciate the help so far, if you guys see anything else I should be checking feel free to add, but I feel better that I didn't screw up some basic setting (so far).


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#8 dhkaiser

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Posted 23 May 2022 - 12:30 PM

I do have the ASCOM platform installed and have experimented both ways of connecting it, I just ended up going with the PC direct mode on the hand controller which so far has seemed to work.  I'm willing to be schooled on that and corrected though if there's a better way.  I followed a couple of guides and videos that talked through the settings to change in EQMOD to enable pulse guiding and thought I got all of them.

Did you see the error message port not available under mount position?



#9 rgsalinger

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Posted 23 May 2022 - 01:48 PM

If the port was not open then you couldn't calibrate the RA axis, right? Note that the RA calibration worked perfectly but there was no DEC movement.

 

If the PHD settings are correct then I'm wondering about the actual cabling of the mount to the HC and then on to the PC. Maybe the cable is not the correct one (long shot). There are, for example two kinds of ST4 cables and you can mix them up. We have assumed, I think, that the OP is using ASCOM Pulse guiding and not ST4.

 

Rgrds-Ross



#10 jackdaniels3773

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Posted 23 May 2022 - 02:30 PM

Did you see the error message port not available under mount position?

No oddly EQMOD seems to work flawlessly and soon as I register driver and connect, I get all the telemetry from the mount without an issue.  Also running every application in administrator mode as I've found it does weird things if you don't (same suggested in every video and forum I've found so far.)



#11 jackdaniels3773

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Posted 23 May 2022 - 02:35 PM

If the port was not open then you couldn't calibrate the RA axis, right? Note that the RA calibration worked perfectly but there was no DEC movement.

 

If the PHD settings are correct then I'm wondering about the actual cabling of the mount to the HC and then on to the PC. Maybe the cable is not the correct one (long shot). There are, for example two kinds of ST4 cables and you can mix them up. We have assumed, I think, that the OP is using ASCOM Pulse guiding and not ST4.

 

Rgrds-Ross

You are correct I'm using ASCOM pulse guiding, not ST4.  I have the cable running from the mount into the hand controller and then a USB cable running from that to the laptop.  That cable is USB on both ends which I believe means it is a newer hand controller and no serial > USB necessary.  What's very strange is I have absolutely no problems getting any other programs to work once it's all set up, slewing the mount in Stellarium works, I can plate solve in APT (and it detects and syncs with Stellarium on each successful solve).  I can add calibration points to EQMOD and enable tracking from APT which appears to work just fine.  This one remaining thing with PHD2 is the last item I'm having problems with before I start setting up for longer exposures. 


Edited by jackdaniels3773, 23 May 2022 - 02:36 PM.


#12 larryjh

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Posted 23 May 2022 - 02:53 PM

Where was the scope pointing when the calibration was run?  I know some have said there was no movement in DEC but to me it looks like it moved for 2 steps and the movement was around 180 degrees from the RA movement.  The only place I think that could happen would be if you were pointing at the north celestial pole, i.e., the mount was in zero position.



#13 jackdaniels3773

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Posted 24 May 2022 - 09:06 AM

Where was the scope pointing when the calibration was run?  I know some have said there was no movement in DEC but to me it looks like it moved for 2 steps and the movement was around 180 degrees from the RA movement.  The only place I think that could happen would be if you were pointing at the north celestial pole, i.e., the mount was in zero position.

Hmmmm, I'm 99% sure that wasn't the case because for most of the night I had it pointed in several spots and reasonably certain I had it centered on the Leo Triplets when first trying to get PHD2 to work.  But I will make certain that's not the case the next time I give this a try.  It's been raining a lot the past couple days and I won't get a chance to try any of this out again until at least Friday.



#14 michael8554

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Posted 25 May 2022 - 08:57 AM

The first thumbnail shows that Cal was at Dec = 12.9, which is close enough to the recommended "close to Dec = 0" for Cal

 

The reported RA guidespeed was 7.728arcsec/sec, which is close enough to the 7.5arcsec/sec setting.

 

But Dec guidespeeed was an enormous Dec = 52.443arcsec/sec.

 

And the Dec Cal was at 180 degrees to RA instead of being at 90 degrees.

 

So Dec commands are going to the RA axis.

 

Check the mount only slews in RA, and only in Dec, when controlled by the handset.

 

Go into the PHD2 Tools/Manual Guide menu and set the Pulse size to 5000.

 

Each single press of the NSEW buttons should move the mount, holding down doesn't send continuous pulses, so you may need multiple presses before seeing consistent motion.

 

Watch the star in the PHD2 display and confirm it moves in the correct directions for N and W.

 

Any Dec Backlash may require multiple presses until Dec moves.

 

Report back.


Edited by michael8554, 25 May 2022 - 08:58 AM.

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#15 rgsalinger

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Posted 25 May 2022 - 04:53 PM

If you want to check for baclash I would recommend the star cross test instead. I don't really see that's the problem here, though. I think that something is not wired correctly between the computer and the mount. I recommend getting the shoestring cable and bypassing the HC for best results. I found, the one time I tried to use the HC/direct method, that it didn't work properly. I wish I could remember exactly what the problem was. I misplaced my shoestring cable and that was that. 

 

Rgrds-Ross



#16 jackdaniels3773

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Posted 27 May 2022 - 02:09 AM

I want to genuinely thank everyone in this thread and specifically my buddy James for all the help sorting this one out.  Turns out my SNR on the guide cam was far too low and probably picking up noise instead of a star during calibration, even with a bad pixel map.  I increased the SNR from 6 to 20 and lowered my gain from default of 95 to 65 to decrease noise and had almost immediate success after PA in sharpcap.  Also unrelated to this original post, I've been having trouble with EQMOD randomly stopping tracking after about 10 - 15 minutes with no warning, found a forum post tonight that mentioned disabling limits and increasing the Windows Process Priority in EQMOD to "High".  I'm not sure which of these fixed the problem but EQMOD linked up and tracked dead on all night with no problems.  I'm going to say this one is fixed for now.

Attached Thumbnails

  • 5-27PHD.png

Edited by jackdaniels3773, 27 May 2022 - 02:11 AM.

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