Pegasus Astro NYX-88 mount, also an issue with calibration, to be continued

[Philippe ANGERS]

Hello,

I'm starting this new thread in order to analyze what has been done yesterday and find out if most of the issues have been solved or if there're still things to fintetune.

The previous thread was this one : 

- Help needed with my new Pegasus Astro NYX-88 mount, also an issue with calibration

Here's the link of last night session, certainly more helpfull to analyze my mount behaviour :

- https://openphdguiding.org/logs/dl/PHD2_logs_5Y87.zip 

There is still room for improvement in terms of focus, which should have a slight impact on the shape of the stars and, as a result, on the stars as they are provided by the OAG to the guide camera.

Last night was clear, but not exceptional. Can we already draw some conclusions?

This time, the guiding was more like normal guiding.

Thank you in advance for your analysis and suggestions.

Philippe

[pollya...@gmail.com]

Hello Phillipe,

In your calibration step, you set . . . 

Assume Orthogonal Axes = yes

This seems unwise to me, bu t I'm sure the experts will comment more.

Cheers,

- Jack T

[Philippe ANGERS]

Hello Jack,

Ouch, you may be right, I think that Bruce (or someone else)  mentioned this in his recommandations in my previous post...

However, I don't know what's the impact of this setting on the whole calibration process...

Philippe

[Brian Valente]

>>>However, I don't know what's the impact of this setting on the whole calibration process...

It can be significant, but there's no way to tell until you run a calibration with this disabled. 

Instead of PHD measuring your actual orthogonality, it's a 'cheat' saying "just assume the axes are perfectly perpendicular. That may or may not be entirely true, but yes you should follow Bruce's prior recommendation and disable it.

Generally imo you should never use 'assume axes orthogonal' unless you have a legitimate reason for doing so. 

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Brian Valente

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[Philippe ANGERS]

Ok, I will uncheck this option for the next clear night!

Too bad I forgot this setting...

Clouds came in today, so, it's a no-go for tonight...

Philippe

[Bruce Waddington]

It looks to me like you haven't made any progress with your camera-related issues so you are still being hampered by too many lost-star events and too few usable guide stars.  That said, you were able to get enough of a workable guide session starting at 21:39 for us to get some insight.  Unfortunately, that looks very much like the problems we found in an earlier post for the same mount:

https://groups.google.com/g/open-phd-guiding/c/cND5EGAKVO8

It's a big disconcerting that we have back-back situations with the same mount and the same very large periodic error in RA.  Here's what yours looks like:

So it's a nearly identical case of a 40 arc-sec peak-peak tracking error with a period of around 430 seconds.  You can see this error imprinted on the native tracking performance during the night:

So, again, this will need to be taken up with the mount manufacturer.  

As Brian said, checking the "assume orthogonal" option is just a feel-good band-aid.  It means you won't see an alert about orthogonality error, but the error is still there.  The only difference is that we won't know how bad it is.  The error is caused by the large amount of periodic error that causes the RA axis to be going "too fast" or "too slow" depending on where it is in the phase of the sine-like periodic error.  Since you have no way to know what the gear phase is, there's no way to do a calibration only during the brief periods when the RA axis is tracking accurately.  

Regards,

Bruce

[Ventura Valderrábano Ornedo]

Thanks you.

I will send this data to the retailer and then to the manufacturer. 

Regards.

Ventura Valderrábano Ornedo 
ventura.a...@gmail.com 

+34 607142000

To view this discussion visit https://groups.google.com/d/msgid/open-phd-guiding/3e138cdd-dc4b-43d3-93ee-50bde496c58an%40googlegroups.com.

[Philippe ANGERS]

Hello Ventura,

That would be nice, because George KARANTZALOS from Pegasus Astro support, with whom I used to exchange since buying the mount for pre sale advice, since last summer, doesn't want to reply anymore and is probably convinced that I'M the problem an NOT the mount...

A month ago, he told me that Pegasus would accept a return of the mount BUT, if they find out that I misused the mount, after all their tests listed in a PDF file, I would be charged 250 euros + shipping back !!!

And you can understand that I can't take the risk of that...

The reason why I needed and still need the analysis of experiemented people.

My retailer in France is Pierro Astro, and he won't do anything regarding the mount except trasnfer my mail to Pegasus...

I sent to George an email this morning with Bruce analysis.

Philippe

[Philippe ANGERS]

Hello Bruce,

I have taken a look at ToupTek reply earlier in January when I sent an email to explain that I couldn't use their driver labeled "ASCOM" (see screenshot below), as the Gain value in PHD2 is grayed out, and I have kept using the other "ToupTek Camera" with very few settings just "8bits or 16 bits" but at eatI could change the gain in PHD2.

They were saying agin that ilictly either I was the problem and not their camera or the... mount !

Anyway the mount is not responsible of the fract that this field is locked and I can't change gain...

Changing fgain from 0 to 100 on their driver GUI before using the camera in PHD2 didn't change anything for the image in PHD2...

Not to mention the beginning of their explanation, which I still don't understand...

Here's waht they were replying :

<tpa-s...@touptek.com> 2026-01-04 09:19:36(GMT+08:00)写道

Regarding input values: the gain range in PHD2 is 0–100, corresponding to 100 to the maximum gain value in Toupsky. Therefore, the gain setting in PHD2 can be understood as a percentage—i.e., "using x% of the maximum gain." The gain value in the ASCOM driver follows the same principle.

Any settings made in Toupsky have no relationship with the settings when connecting the camera in PHD2. The failure to calibrate may stem from the mount. If you can see star points in the image, the inability to calibrate is most likely due to the mount or other settings.

If you find that the gain or other settings in PHD2 are grayed out, it is likely because your camera is in a looping exposure state, during which PHD2 does not allow the user to modify certain key settings. You need to stop the exposure, verify that the parameters in the gain and calibration calculator are correct and reasonable, and then restart the exposure.

Additionally, if you see a "not enough movement" prompt in PHD2, you can try increasing the guiding rate in the mount control settings.

[Bruce Waddington]

Ok, let's come back to the camera problem.  You haven't uploaded the PHD2 logs when you were trying to use the ToupTek ASCOM driver so I'm having to guess here.  Based on the screen shot, I don't think you're connected to the ASCOM driver, I think you're connected to the native driver.  Did you separately download and install the ASCOM driver.  That's not the same as ToupTek Sky or any of the other ToupTek apps, it's a separate piece of software that must be downloaded from their web site and installed.  In PHD2, the ASCOM drivers are identified by '(ASCOM)' in the name and I don't see that in your screen shot.  If you get that sorted out, then you should be able to use the ASCOM driver gain control successfully.  Going forward, you must upload your PHD2 log files for this sort of thing regardless of whether you actually did any guiding.

Bruce

[Philippe ANGERS]

Hello Bruce,

I would like to, but as explained in my previous post, when I'm using the ASCOM ToupTek driver, first the Gain field in PHD2 is locked (grayed out), and second, the background from the camera is so grainy that I cannot distinguish stars!

I've been told there that it's not very important, because it's more advised to use Star prfile to help focusing.

Was it grainy and unexploitable compared to the image from the other ToupTek driver with the which the background is almost black and I can see the stars, be they properly (I didn't say perfectly ! ;-) ) focused or, conversely, defocused and looking like donuts!!

Here's what I get with the ToupTek driver I'm currently using (let's forget the other data):

And here's what I would get with the other (let's forget again messages and figures):

Of course, the most important is the HFD figure, but is this normal to get a very grainy image everytime?

One more question, the gain : I can't change it in PHD2 and whatever the value selected in the ASCOM ToupTek driver GUI, it doesn't make any difference on the image displayed in PHD2, and the gain field is permanently locked, what make me think something is not communicating properly between the driver and PHD2...

When I asked them an explanation, they replied with the cryptic explanation mentioned above!

Do you undestand what they mean, because, I don't!

Philippe

[pollya...@gmail.com]

Hello again Phillipe,

I suggest you also install the 32bit (x86) Touptek native driver.

Cheers,

- Jack T

[Philippe ANGERS]

Hello Jack,

What would adding the 32 bits driver in a 64 bits operating system, bring ?

Philippe

[Bruce Waddington]

I'm still concerned that you're fumbling around, but I may be mistaken.  The gain field in PHD2 is disabled because the ToupTek camera driver/SDK is telling PHD2 there is no programmable gain control.  The 2.6.14 version of PHD2 is using ToupTek software that was available in November 2025 so it's possible this situation has been corrected in a later version from ToupTek.  There's nothing we can do about that right this minute.  This is one of the reasons we encourage people to use the ASCOM drivers from the camera manufacturers.  So if you want help, I would like to see the following:

1.  Connect PHD2 to the ASCOM driver from ToupTek.  That driver has to be separately installed, it isn't just going to show up on your computer.  It will have a name in the PHD2 camera list that ends with (ASCOM).  If you don't see an entry like this in PHD2, then the ASCOM camera driver isn't installed properly.

2.  Open the ASCOM setup dialog for that driver and adjust the gain setting downward - try going to zero.  Not a gain setting in some other app, it has to be in the setup dialog hosted by the ASCOM driver.  To see that dialog, open the Connect Equipment dialog in PHD2, connect to the ASCOM camera driver, then click on the camera setup icon that is just to the left of the Connect Camera button.

3.  Build a dark library for this setup.  You can just restrict the dark library exposure times to a range of 1-3 seconds.

4.  Upload the guide and debug log files to our server so we can see what you did.

Bruce

[Bruce Waddington]

Sorry, I left out the obvious step at the end, before uploading the log files - take a few sample exposures of a nighttime sky using exposures in the range of 1-3 seconds.

Bruce

[Philippe ANGERS]

Bruce,

I think you didn't carefully paid attention to all my screenshots and explanation in my previous post my dear Bruce! ;-)

I understand, you are certainly very busy with all these posts ! ;-) 

1.  Connect PHD2 to the ASCOM driver from ToupTek.  That driver has to be separately installed, it isn't just going to show up on your computer.  It will have a name in the PHD2 camera list that ends with (ASCOM).  If you don't see an entry like this in PHD2, then the ASCOM camera driver isn't installed properly. --> done what you see on my screenshot in my previous post is exactly the ASCOM driver intalled through the setup provided by ToupTek on their website, and once installed you get this entry in PHD2 menu :

If you don't use this one there is another driver, what you call the "native" driver at the bottom of the list simply labeled "ToupTek camera" and this one simply allows to select between 8 or 16 bits camera mode.

When the setup installs the ASCOM driver we can see that it copies the Toupcam.dll and indeed, it's there in Program Files x86,  and I did it this morning and installed the latest driver that is available since the end of february, I didn't know, so I took advantage of this to install it.

2.  Open the ASCOM setup dialog for that driver and adjust the gain setting downward - try going to zero.  Not a gain setting in some other app, it has to be in the setup dialog hosted by the ASCOM driver.  To see that dialog, open the Connect Equipment dialog in PHD2, connect to the ASCOM camera driver, then click on the camera setup icon that is just to the left of the Connect Camera button. --> also done, and my previous screenshots were also created doing exactly that :

3.  Build a dark library for this setup.  You can just restrict the dark library exposure times to a range of 1-3 seconds.

4.  Upload the guide and debug log files to our server so we can see what you did.

5.  Take a few sample exposures of a nighttime sky using exposures in the range of 1-3 seconds

I have to do these last 3 steps the next clear night I suppose?

I could do that tonight but the sky is cloudy so no stars would be visible!

Let me know and I will do it and upload th log files.

Thanks Bruce four your kind help,

Philippe

[Bruce Waddington]

Ok, if you're using the ASCOM driver, then it's an issue  between you and ToupTek.  PHD2 treats all ASCOM camera drivers the same way, so you can continue the dialog with them without having everyone being confused about why PHD2 has disabled the gain setting.

Good luck,

Bruce

[Brian Valente]

Philippe

Just to clarify Bruce's last comment and overall point:

The camera driver (specifically the ASCOM example) is supplied by and supported by ToupTek. PHD has no control over what is displayed or what settings are available. You need to show them the asom driver results. Either there is a problem with that driver, or you haven't set it up properly.

To view this discussion visit https://groups.google.com/d/msgid/open-phd-guiding/d1e7105b-ba74-4d77-8c51-79146fd784e1n%40googlegroups.com.

[Brian Valente]

Phillippe

you are in luck because I have a touptek guide camera.

using the touptek ascom driver i can set the gain in the ASCOM setup just fine using the wrench settings next to the ascom touptek camera.

I just:

- installed the touptek ascom driver

- then copied the latest x64 dll from their website into the phd folder

[Brian Valente]

using the native driver, i can set the camera gain in the advanced settings->camera gain (native driver is the only option that enables this)

so at least for the 678m, touptek all checks out fine here with ascom and native drivers.

[Philippe ANGERS]

Hello,

@brian Valente: ok, great to find someone with a ToupTek camera.

You're showing with your first screenshot what I mentioned in my previous post, but, indeed, even though we can adjust gain in the ASCOM driver, does it lock in the PHD2 interface the Gain field!?

This is the most important thing I would like to clarify with you! :-) 

If so, I can give it another try setting the gain in the ASCOM driver and not trying to change it in PHD2 alas, but if it works that way, so be it.

But, if you tell me that you are using the ToupTek ASCOM driver AND that you can also change the gain in the Camera tab of PHD2, I do have a bug or a problem with the driver!

Let's also clarify another methodological point : how did you install the ASCOM driver ?

Because as far as I know ToupTek ONLY provides on their website a setup package and not a dll alone just like the "native" driver mentioned in my previous post, and below in this post!

Talking about this "native" driver, I also tried last atfernoon to manually install the Toupcam64 and x86 DLL following instructions from ToupTek when you click on the red triangle

But for both I had an issue with PHD2!!

For the 64 bits driver it simply crashes PHD2 with a stop code when you start it, and for the second, PHD2 starts but a warning is displayed on the image...

As suggested by someone, you can't use both drivers in the same PHD2 directory as you need to rename them with the same name as explained by ToupTek in the instructions...

Thanks for your feedback about the ASCOM driver

Philippe

[Brian Valente]

>>>But, if you tell me that you are using the ToupTek ASCOM driver AND that you can also change the gain in the Camera tab of PHD2, I do have a bug or a problem with the driver!

I think you have a misunderstanding of camera controls. Let me clarify how the camera connections work.

When using the ASCOM connection the camera settings are completely outside PHD. The gain settings are set in the ASCOM driver settings window. PHD (or any other application) does not have any information on what this setting is. 

the gain setting in the camera tab is active only when using the native driver (i.e., choosing touptek as camera type, not ascom touptek), and will be enabled. 

If you choose the touptek native camera, you can set the gain within PHD. if ASCOM, you set the gain in the ascom driver settings, not in PHD. 

I have tested the native driver and can see changes to the gain in the camera settings correctly carry into the fits file header.

Regarding installation, I used the natifve x86 driver and installed according to their instructions. ascom driver was just running the installer.

At this point, I think it's clear the touptek camera and gain work correctly within PHD. 

To view this discussion visit https://groups.google.com/d/msgid/open-phd-guiding/6f7df75c-1890-4b89-9b91-9cca26d1fb22n%40googlegroups.com.

[Philippe ANGERS]

Brian,

No I didn't know, and of course we cannot know everything! ;-)

I've just discovered the subtleties of the drivers in relationship with PHD2 and didn't know there was native and ASCOM drivers and that they were not supposed to behave the same way.

Ok, now it's really clear in my mind.

One last question, if I may: since the ASCOM driver allows you to adjust the camera gain independently of PHD2, we can assume that it must adjust it correctly, right?

Should we see a difference in the appearance of the image in PHD2?

The recommended gain values are in the range of approximately 30-40%. Does this apply in the same way to the gain within the ASCOM driver?

The judge is the peak value displayed in PHD2, so we need to use Star Profile to check the impact of the focus setting, but if I see that it is saturated, do I need to lower the gain on the ASCOM driver until the value is the best possible?

Is that correct?

Philippe

[Brian Valente]

Philippe

Here are the relevant questions for PHD:

>>.The judge is the peak value displayed in PHD2, so we need to use Star Profile to check the impact of the focus setting, but if I see that it is saturated, do I need to lower the gain on the ASCOM driver until the value is the best possible?

You should use a non-saturated star. The best approach is to use the auto-select guidestar, which will pick the best guidestar for your settings. 

>>>Should we see a difference in the appearance of the image in PHD2?

not necessarily. higher gain should produce a brighter image, all else being equal. 

Here are questions outside of PHD/for touptek (my own color commentary added)

>>>One last question, if I may: since the ASCOM driver allows you to adjust the camera gain independently of PHD2, we can assume that it must adjust it correctly, right?

Presumably, but that's within the touptek ascom camera driver, nothing to do with PDH

>>>The recommended gain values are in the range of approximately 30-40%. Does this apply in the same way to the gain within the ASCOM driver?

Not sure whose recommendations these are, but these questions are both for Touptek. 

All that being said, Going back to your original post, which is to improve guiding on a problematic mount. I'm not sure how chasing camera gain is going to make a difference to your results. Gain might make a difference on the margin particularly if you have low guidestar snr or a lot of lost star events, but afaik you don't have these. Not that long ago you couldn't even change the gain on a guide camera, and many many people have guided successfully. This is still true today. 

You can also use the same touptek ascom connection and guide camera, open it in nina or similar, and see what looping exposures look like there.

I don't think there's much more we can offer related to your camera and gain in terms of PHD and guiding results. The rest of that is now up to you. Based on the last guidelogs you submitted, the camera is working well enough, and fiddling with gain settings isn't going to materially change your guider outcome.

Brian

To view this discussion visit https://groups.google.com/d/msgid/open-phd-guiding/259a4c60-2947-41ed-ae72-e47e55bed25bn%40googlegroups.com.

[Philippe ANGERS]

Hello Brian and Bruce,

I am sorry for persisting in trying to understand, and Brian,  I thank you for taking the time to explain the management of native and ASCOM drivers in interaction with PHD2. :-)

I think I will change the camera because ToupTek support does not seem able to provide me with the answers I need.

I will not bring up this subject again here.

However, I would like to point out that the purpose of all these questions was to do everything possible to isolate any possible responsibility on the part of the ToupTek driver's guidance management, in order to properly validate Bruce's feedback on the mount's behaviour with regard to the periodic error.

Can we conclude that despite all the efforts I could make to try to improve the situation, they will remain more or less futile because the mount has too strong and unpredictable periodic error, or are there still areas where I could do something?

Having had no feedback from Pegasus for a week, I think they are going to drag their feet and that I will have to fight with my dealer for a return without the threat of huge diagnostic and return costs brandished by Pegasus, even though the mount is still under its legal warranty period...

Thanks in advance for your opinion or Bruce's, and we're definitely in this forum's area of expertise! ;-)

Philippe

[Brian Valente]

Hi Philippe,

We are happy to assist you. While the problems we discussed began with your observations in PHD2, it has become clear that the issues reside outside of the software itself.

In my opinion, your experiences are not uncommon, and these issues should be solvable with the vendors. Strainwave mounts often exhibit high periodic error (PE), and most manufacturers will take steps to rectify it if the PE is found to be unusually high. Pegasus should be no different in this regard.

Regarding ToupTek, they generally produce quality cameras with many satisfied users. Ultimately, you should pursue whichever remedy you feel is best for your setup.

Brian 

To view this discussion visit https://groups.google.com/d/msgid/open-phd-guiding/7cee16c4-172f-4293-b1c9-8d22c4f5d938n%40googlegroups.com.