Date   

Re: issue with APPM

Ray Gralak
 

This is an issue with the meridian delay and it was fixed in this beta version of APCC Pro:

http://www.apastrosoftware.com/apcc_download/APCC_Pro_Setup_1.7.2.5.exe


-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...]
Sent: Tuesday, September 10, 2019 5:11 PM
To: ap-gto@...
Subject: [ap-gto] issue with APPM



I am having an issue when trying to run point mapping in APCC Pro and was wondering if anybody has seen this
behavior before. It starts by plate solving a point near the zenith. That works fine. Next it slews to a point near the
southeast horizon. That works fine too. Then it slews all over the sky for several minutes. It actually can take
around 4 to 5 minutes before it finally ends up at a second point which it solves and then once again slews all
over the sky for another 4 ro 5 minutes before solving a third point. I tried to do a large point mapping run and the
sun started coming up before I could finish. This has happened on several nights when I've tried to run a large
model. I live in Florida so this time of year I get very few clear nights to try this especially due to my work
schedule. Any ideas would be greatly appreciated.

Thanks,

Scott


Re: Does pulse guide work with CCDSoft?

Ray Gralak
 

Hi Tom,

It seems that in CCDSoft, there is not option to use that. There is an option for DirectGuide. Is that the same?
No they are not the same!

-Ray Gralak
Author of APCC (Astro-Physics Command Center): http://www.astro-physics.com/index.htm?products/accessories/software/apcc/apcc
Author of PEMPro V3: https://www.ccdware.com
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver


-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...]
Sent: Tuesday, September 10, 2019 1:45 PM
To: ap-gto@...
Subject: [ap-gto] Does pulse guide work with CCDSoft?



Hi,

For some reason TheSkyX pro with camera add on no longer users my autoguider chip with the STL11000.

So, until TheSky fixes this, I have to use CCDSoft which works just fine. The thing is I never had good results
using the relays in the camera for autoguiding so with TheSky, I used pulse guide.

It seems that in CCDSoft, there is not option to use that. There is an option for DirectGuide. Is that the same?

Thanks, Tom


Re: issue with APPM

Tyrel Smith
 

I had this not too long ago as well. I set a 2 degree RA offset and that solved the problem for me. Otherwise the mount kept meridian flipping over and over and over and took forever. With the RA offset it measures all points on one side of the meridian, then the other. Don't know if this is a sanctioned method. Maybe someone else will chime in with a better understanding/solution.

On Tue, Sep 10, 2019 at 9:14 PM cafdeefdcma7pr2oqcs7pdfwwxd2v3a2pn4oexfg@... [ap-gto] <ap-gto@...> wrote:
 

I am having an issue when trying to run point mapping in APCC Pro and was wondering if anybody has seen this behavior before. It starts by plate solving a point near the zenith. That works fine. Next it slews to a point near the southeast horizon. That works fine too. Then it slews all over the sky for several minutes. It actually can take around 4 to 5 minutes before it finally ends up at a second point which it solves  and then once again slews all over the sky for another 4 ro 5 minutes before solving a third point. I tried to do a large point mapping run and the sun started coming up before I could finish. This has happened on several nights when I've tried to run a large model. I live in Florida so this time of year I get very few clear nights to try this especially due to my work schedule. Any ideas would be greatly appreciated.

   Thanks,

          Scott 


Re: MACH1 and 1100GTO

matt brown
 

thanks for the thorough response.  I kind of figured there wasn't a bad choice between the two.

thanks,
matt


Re: Does pulse guide work with CCDSoft?

Tom Blahovici
 

Well, the last time I used theskyx it worked find eith my autoguider chip. I did nothing different and all of a sudden the built in autoguide hip on my stl11000 is not being used by the sky.
CcdSoft works fine, so something in the ccdsoft software changed. I have not had luck with the relays so was using pulseguide with thesky, but since it is not working anymore, I want to use it with ccdsoft. Seems not possible.
The good news is that support for theskyx is now helping. I have to wait for the rain to stop to try it.
No rain beautiful skyscrapers all summer. When I set up my scope in its semi permanent observatory it decided to rain and be cloudy all the time....
Regards, Tom


issue with APPM

cafdeefdcma7pr2oqcs7pdfwwxd2v3a2pn4oexfg@...
 

I am having an issue when trying to run point mapping in APCC Pro and was wondering if anybody has seen this behavior before. It starts by plate solving a point near the zenith. That works fine. Next it slews to a point near the southeast horizon. That works fine too. Then it slews all over the sky for several minutes. It actually can take around 4 to 5 minutes before it finally ends up at a second point which it solves  and then once again slews all over the sky for another 4 ro 5 minutes before solving a third point. I tried to do a large point mapping run and the sun started coming up before I could finish. This has happened on several nights when I've tried to run a large model. I live in Florida so this time of year I get very few clear nights to try this especially due to my work schedule. Any ideas would be greatly appreciated.

   Thanks,

          Scott 


Re: Does pulse guide work with CCDSoft?

Stuart Heggie <stuart.j.heggie@...>
 

Tom, I believe that DirectGuide is for the Bisque mounts only. I think you need PulseGuide or Relays with CCDSoft5 and an AP mount.

I've used PulseGuide with my AP900GTO and TSX but not recently. Did something change with an update to TSX?


On Tue, 10 Sep 2019 at 17:08, tom_b@... [ap-gto] <ap-gto@...> wrote:
 

Hi,

For some reason TheSkyX pro with camera add on no longer users my autoguider chip with the STL11000.

So, until TheSky fixes this, I have to use CCDSoft which works just fine.  The thing is I never had good results using the relays in the camera for autoguiding so with TheSky, I used pulse guide.

It seems that in CCDSoft, there is not option to use that.  There is an option for DirectGuide.  Is that the same?

Thanks, Tom


Re: APCC Pro included with Mach2GTO

Terri Zittritsch
 

Marj, thanks so much..  that was going to be my next question, but I thought rather than bother you for something that I might find on the site, I looked it up on the A-P site and the Mach 2 listed it as only the standard as being included…   So if you’re changing this to the pro to be included, that’s great.

Terri

On Sep 10, 2019, at 4:57 PM, Marj marj@... [ap-gto] <ap-gto@...> wrote:


The Mach2GTO will ship with APCC Pro so that these mounts will have the benefit of dual-model pointing and tracking rate correction even with the telescope in the counterweight UP position. This will allow the Mach2GTO to take full advantage of its ability to achieve unguided imaging, the holy grail. 

 

I have updated the website to reflect this. 

 

Clear Skies,

 

Marj Christen

Astro-Physics, Inc

11250 Forest Hills Rd

Machesney Park, IL 61115

Phone: 815-282-1513

Fax: 815-282-9847

www.astro-physics.com

 




Re: APCC Pro included with Mach2GTO

Cheng-Yang Tan
 

Any special upgrade price for those who own an AP1100AE and APCC? Hint hint :)

cytan

On Tuesday, September 10, 2019, 03:55:05 PM CDT, Marj marj@... [ap-gto] wrote:


 

The Mach2GTO will ship with APCC Pro so that these mounts will have the benefit of dual-model pointing and tracking rate correction even with the telescope in the counterweight UP position. This will allow the Mach2GTO to take full advantage of its ability to achieve unguided imaging, the holy grail.

 

I have updated the website to reflect this.

 

Clear Skies,

 

Marj Christen

Astro-Physics, Inc

11250 Forest Hills Rd

Machesney Park, IL 61115

Phone: 815-282-1513

Fax: 815-282-9847

www.astro-physics.com

 


APCC Pro included with Mach2GTO

 

The Mach2GTO will ship with APCC Pro so that these mounts will have the benefit of dual-model pointing and tracking rate correction even with the telescope in the counterweight UP position. This will allow the Mach2GTO to take full advantage of its ability to achieve unguided imaging, the holy grail.

 

I have updated the website to reflect this.

 

Clear Skies,

 

Marj Christen

Astro-Physics, Inc

11250 Forest Hills Rd

Machesney Park, IL 61115

Phone: 815-282-1513

Fax: 815-282-9847

www.astro-physics.com

 


Does pulse guide work with CCDSoft?

Tom Blahovici
 

Hi,

For some reason TheSkyX pro with camera add on no longer users my autoguider chip with the STL11000.

So, until TheSky fixes this, I have to use CCDSoft which works just fine.  The thing is I never had good results using the relays in the camera for autoguiding so with TheSky, I used pulse guide.

It seems that in CCDSoft, there is not option to use that.  There is an option for DirectGuide.  Is that the same?

Thanks, Tom


Re: MACH1 and 1100GTO

Roland Christen
 

Both mounts would work nicely for you. The Mach2 is more foolproof so making mistakes in calibration of Sync won't get you lost. It is easy to recover with the Mach2 encoder mount because it continually keeps track of where the axes are pointed, even when the clutches are loosened and you move the scope around manually.

The key to getting good astrophotos is to nail the polar alignment. That can be done any number of ways, either with our polar scope, or with electronic devices (which require a computer). You can also do old fashioned drift alignment, but that requires a bit of patience.

Once you have good polar alignment, limit your exposures to the time period that produces round stars and simply stack many images. Typically almost any deep sky object will require at least 1 hour of total exposure, and for fainter ones perhaps as many as 5 - 10 hours. It matters little if you do 1 x 2 minutes or 2 times 10 minutes when using the modern Cmos imagers. Although DSLRs do work to some extent, they are nowhere near as good as a dedicated astrocamera, and a lot of those are getting quite affordable. Spring for the cooled version since noise is the #1 killer of good deep sky images.

Rolando



-----Original Message-----
From: matthewcbrown@... [ap-gto]
To: ap-gto
Sent: Tue, Sep 10, 2019 2:17 pm
Subject: [ap-gto] MACH1 and 1100GTO



Hi All,
 
I’m looking for some advice on mounts, specifically MACH2 and 1100GTO.
 
I am a beginning imager.  I image at home and would roll the mount, tripod, etc. fully assembled out of the garage whenever I image and use a RAPAS for polar alignment.  I don’t want to add a computer to the setup. I have a MGEN autoguider but would prefer to not guide.  I plan on controlling the mount through a tablet or smartphone.
 
I’m not after world class images nor would I be collecting scientific data. Either mount would carry the imaging train (currently a DSLR and Stowaway and work up to a C11 someday). I’m located in Iowa so seeing won’t be the greatest.
 
Would the absolute encoders on the MACH2 be worth the additional cost for this situation?  After reading about absolute encoders it seems they are most beneficial to advanced imagers or amateurs actually doing science.

Thanks,
matt



Re: Guiding guidance for Mach2?

Roland Christen
 

Hello Terri,

 So my net question is, do encoders improve guiding accuracy or is it just making the job easier?   Can I expect unguided shots at 1000mm focal length of how long (1-2-3 minutes?)
Of course the encoders improves the guiding accuracy and makes the guiding software's job easier.
Unguided imaging requires a model, and for that we have APCC Pro, so yes, you should be able to do unguided imaging.
Can a mount with high res encoders tame bad seeing? The simple answer is no. If you have 0.6 seeing you won't get 0.2 arc sec guiding. However, the mount won't degrade to 0.9 arc sec guiding either.
Rolando

-----Original Message-----
From: Terri Zittritsch theresamarie11@... [ap-gto] <ap-gto@...>
To: chris1011@... [ap-gto] <ap-gto@...>
Sent: Tue, Sep 10, 2019 1:28 pm
Subject: Re: [ap-gto] Guiding guidance for Mach2?

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Hi Rolando, thanks for the response and sorry if my question wasn’t clear… but it’s not been very clear in my mind either so I’ll try again and then probably noodle on it some more.   I’m trying to understand the benefits of absolute encoders to guiding and tracking for A-P.     I did re-read your post.   I understand the mount accuracy benefits, and to get my 0.6 RMS or better tracking I typically can’t have 3” excursions on the Atlas (takes a long time to RMS that out) and can avoid them (mostly) 30 degrees around zenith but lower towards the horizon things get horrible..  And almost always 3 or more hours into a session something goes horrible in my tracking and I never really figure out why..  But I know the mechanicals are not so precise, backlash is pretty high, stiction is high in the cold weather, i have cables all over the place getting stiff.   I throw away sometimes 30% of frames due to mysterious events which is why I’m pursuing a better mount.     But  I do use the TEC140 at prime focus with your AP flattener which gives me right around 1000mm of focal length, and my stars are usually pretty darn good (again, around the zenith).   I also use an 8” sct at 1300mm with the same mount successfully.. again, keep rate is lower.    Given vt skies, I’d like to not loose 30% of my frames (life with clear skies is literally too short here).    Some day after retiring I’ll move to somewhere with better skies and no freezing weather.   
Where i see the benefits of the machining quality is not having so much backlash or periodic error, so less work for guiding (but many premium mounts can do this)..     I think the benefits of absolute encoders are only the total elimination of back lash and periodic error, since you're making sure with a closed loop system that the correction or movement resulting at the shaft is the correction or movement requested and not just a calculated movement of the worm.   As long as your internal clock and encoder resolution is high enough to achieve the design goal, you have a system which only needs active guiding for polar alignment inaccuracy (and maybe wind if the reaction time is quick enough).   I think pointing accuracy is not all that important in this era of plate solving.    I can get 50 pixel pointing in 3 or 4 iterations in a couple of minutes which is good enough for my images.   So is the net benefit of encoders, providing less work for the guiding system?   And the question is how important is the encoder versus the wonderful machining and accuracy of a premium mount such as you make?    So my net question is, do encoders improve guiding accuracy or is it just making the job easier?   Can I expect unguided shots at 1000mm focal length of how long (1-2-3 minutes?)   I guess this is my ultimate question.   Not changing my mind at all, and my supplier has contacted me already so I am getting excited.. but as a 39 year plus employee of semiconductor biz, everything tech gets me excited.
Thanks,Terri



On Sep 10, 2019, at 12:24 PM, chris1011@... [ap-gto] <ap-gto@...> wrote:

Hi Terri,
I'm not quite sure what your question is. If you have a mount that tracks at 0.1 arc sec rms like my first chart, then you have an excellent mount. If 0.6 arc sec rms meets your needs, then again you have the mount already for your application.
Where the Mach2 comes in is at the precision level where the system can be controlled to 0.1 arc sec pk via commands by external software. 0.6 rms sounds low but in reality the peak excursions will generally be 5 times that, around 3 arc sec pk-pk. That works ok for short focus instruments of around 500mm, but falls way short when using longer scopes that have inherent high resolution. 

The original question was how to set up PHD2 for guiding with this mount. The simple answer is to use 2 sec or longer guide exposures so that a good guide star centroid can be calculated. Shorter exposures are not recommended, even in great seeing conditions. The rest I explained in my previous post.

Rolando



-----Original Message-----
From: Terri Zittritsch theresamarie11@... [ap-gto] <ap-gto@...>
To: chris1011@... [ap-gto] <ap-gto@...>
Sent: Tue, Sep 10, 2019 11:04 am
Subject: Re: [ap-gto] Guiding guidance for Mach2?



Hi Rolando,I’ve thought about this a bit now, and I know chasing the seeing can be counter-productive when doing astrophotography.     If you have a mount that should be tracking at .25 arc-sec or less, and if the seeing is poor and causing you to make mount corrections of arc-seconds, isn’t this being counter productive?    Now of course I’m assuming perfect polar alignment which is hard to have especially if you’re always portable like me, and every night is different.   But I do use a polar camera/solver that seems to do well, and even with my Atlas can get .6 arc sec tracking with PHD and a 400mm guide scope  around the zenith (+-30 degrees) and have a chart like your first one (maybe not quite so pretty).  As I get towards the horizons all bets seem to be off and the atmosphere takes over and my excursions get much bigger (like your second chart only larger excursions).    
I’m just trying to wrap my head around making all of these large corrections (on your poor seeing night example) and what the encoders are doing for you in this case versus just very precise mechanicals (like A-P has always had).   This looks very much like what I deal with constantly with my atlas and as most nights don’t have great seeing.    All you really want to correct for, is any long term drift due to poor polar alignment or RA speed inaccuracy.     I’m probably not understanding something here.

Terri






On Sep 9, 2019, at 7:50 PM, chris1011@... [ap-gto] <ap-gto@...> wrote:

Trying again.
Rolando


-----Original Message-----
From: chris1011 <chris1011@...>
To: ap-gto <ap-gto@...>
Sent: Mon, Sep 9, 2019 5:46 pm
Subject: Re: [ap-gto] Guiding guidance for Mach2?

I have been guiding with 2 to 5 second exposures using PHD2. 2 sec for guiding on a calm night, up to 5 sec on a night of unsteady air. If you expose for less than 2 seconds, especially on a poor seeing night, you should dial in at least a 2 second delay between exposures. Otherwise the guide star is going to be jumping around a lot because the guide program is going to try to chase the seeing. I have tried as fast as 0.2 sec exposures with no delays, but the guiding is not great. At that exposure level the star's centroid will never stay still even on a good seeing night..

I set my Min Move according to what the atmospheric motion is that night. On a good seeing night it can be as low as 0..1 arc sec.. On a poor night I have it set to around 0.35 arc sec. If you use the Guide assistance, it will give you some very good starting parameters for these settings because it first measures the atmospheric motion and then sets the Min Move accordingly. A really powerful part of the program, I have found..

Aggressiveness setting is usually around 60% +- 10. On a good night i can sometimes set it higher, but above 80% doesn't buy much. 

As far as Algorithms, I have used all of them and find not much difference in performance. 

On a very steady night I have consistently gotten below 0.15 arc sec rms on both axes. Sometimes below 0.1. On the poorest night my guiding is around 0.45 arc sec rms.

Here is a typical result on a good night (4 out of 5 seeing):

And here is a poor night when the seeing was 2 out of 5:


-----Original Message-----
From: wayneh9026@yahoo..com [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Mon, Sep 9, 2019 5:00 pm
Subject: [ap-gto] Guiding guidance for Mach2?

Rolando, any guidance on autoguiding for the Mach2, given it’s absolute encoders? Such as settings for PHD2?

Thanks,

Wayne 

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Re: Guiding guidance for Mach2?

Terri Zittritsch
 

Hi Rolando, thanks for the response and sorry if my question wasn’t clear… but it’s not been very clear in my mind either so I’ll try again and then probably noodle on it some more. I’m trying to understand the benefits of absolute encoders to guiding and tracking for A-P. I did re-read your post.
I understand the mount accuracy benefits, and to get my 0.6 RMS or better tracking I typically can’t have 3” excursions on the Atlas (takes a long time to RMS that out) and can avoid them (mostly) 30 degrees around zenith but lower towards the horizon things get horrible. And almost always 3 or more hours into a session something goes horrible in my tracking and I never really figure out why.. But I know the mechanicals are not so precise, backlash is pretty high, stiction is high in the cold weather, i have cables all over the place getting stiff. I throw away sometimes 30% of frames due to mysterious events which is why I’m pursuing a better mount. But I do use the TEC140 at prime focus with your AP flattener which gives me right around 1000mm of focal length, and my stars are usually pretty darn good (again, around the zenith). I also use an 8” sct at 1300mm with the same mount successfully.. again, keep rate is lower. Given vt skies, I’d like to not loose 30% of my frames (life with clear skies is literally too short here). Some day after retiring I’ll move to somewhere with better skies and no freezing weather.

Where i see the benefits of the machining quality is not having so much backlash or periodic error, so less work for guiding (but many premium mounts can do this). I think the benefits of absolute encoders are only the total elimination of back lash and periodic error, since you're making sure with a closed loop system that the correction or movement resulting at the shaft is the correction or movement requested and not just a calculated movement of the worm. As long as your internal clock and encoder resolution is high enough to achieve the design goal, you have a system which only needs active guiding for polar alignment inaccuracy (and maybe wind if the reaction time is quick enough). I think pointing accuracy is not all that important in this era of plate solving. I can get 50 pixel pointing in 3 or 4 iterations in a couple of minutes which is good enough for my images. So is the net benefit of encoders, providing less work for the guiding system? And the question is how important is the encoder versus the wonderful machining and accuracy of a premium mount such as you make? So my net question is, do encoders improve guiding accuracy or is it just making the job easier? Can I expect unguided shots at 1000mm focal length of how long (1-2-3 minutes?) I guess this is my ultimate question. Not changing my mind at all, and my supplier has contacted me already so I am getting excited.. but as a 39 year plus employee of semiconductor biz, everything tech gets me excited.

Thanks,
Terri

On Sep 10, 2019, at 12:24 PM, chris1011@... [ap-gto] <ap-gto@...> wrote:


Hi Terri,

I'm not quite sure what your question is. If you have a mount that tracks at 0.1 arc sec rms like my first chart, then you have an excellent mount. If 0.6 arc sec rms meets your needs, then again you have the mount already for your application.

Where the Mach2 comes in is at the precision level where the system can be controlled to 0.1 arc sec pk via commands by external software. 0.6 rms sounds low but in reality the peak excursions will generally be 5 times that, around 3 arc sec pk-pk. That works ok for short focus instruments of around 500mm, but falls way short when using longer scopes that have inherent high resolution.

The original question was how to set up PHD2 for guiding with this mount. The simple answer is to use 2 sec or longer guide exposures so that a good guide star centroid can be calculated. Shorter exposures are not recommended, even in great seeing conditions. The rest I explained in my previous post.

Rolando



-----Original Message-----
From: Terri Zittritsch theresamarie11@... <mailto:theresamarie11@...> [ap-gto] <ap-gto@... <mailto:ap-gto@...>>
To: chris1011@... <mailto:chris1011@...> [ap-gto] <ap-gto@... <mailto:ap-gto@...>>
Sent: Tue, Sep 10, 2019 11:04 am
Subject: Re: [ap-gto] Guiding guidance for Mach2?



Hi Rolando,
I’ve thought about this a bit now, and I know chasing the seeing can be counter-productive when doing astrophotography. If you have a mount that should be tracking at .25 arc-sec or less, and if the seeing is poor and causing you to make mount corrections of arc-seconds, isn’t this being counter productive? Now of course I’m assuming perfect polar alignment which is hard to have especially if you’re always portable like me, and every night is different. But I do use a polar camera/solver that seems to do well, and even with my Atlas can get .6 arc sec tracking with PHD and a 400mm guide scope around the zenith (+-30 degrees) and have a chart like your first one (maybe not quite so pretty). As I get towards the horizons all bets seem to be off and the atmosphere takes over and my excursions get much bigger (like your second chart only larger excursions).

I’m just trying to wrap my head around making all of these large corrections (on your poor seeing night example) and what the encoders are doing for you in this case versus just very precise mechanicals (like A-P has always had). This looks very much like what I deal with constantly with my atlas and as most nights don’t have great seeing. All you really want to correct for, is any long term drift due to poor polar alignment or RA speed inaccuracy. I’m probably not understanding something here.


Terri






On Sep 9, 2019, at 7:50 PM, chris1011@... <mailto:chris1011@...> [ap-gto] <ap-gto@... <mailto:ap-gto@...>> wrote:


Trying again.

Rolando


-----Original Message-----
From: chris1011 <chris1011@... <mailto:chris1011@...>>
To: ap-gto <ap-gto@... <mailto:ap-gto@...>>
Sent: Mon, Sep 9, 2019 5:46 pm
Subject: Re: [ap-gto] Guiding guidance for Mach2?

I have been guiding with 2 to 5 second exposures using PHD2. 2 sec for guiding on a calm night, up to 5 sec on a night of unsteady air. If you expose for less than 2 seconds, especially on a poor seeing night, you should dial in at least a 2 second delay between exposures. Otherwise the guide star is going to be jumping around a lot because the guide program is going to try to chase the seeing. I have tried as fast as 0.2 sec exposures with no delays, but the guiding is not great. At that exposure level the star's centroid will never stay still even on a good seeing night..

I set my Min Move according to what the atmospheric motion is that night. On a good seeing night it can be as low as 0.1 arc sec.. On a poor night I have it set to around 0.35 arc sec. If you use the Guide assistance, it will give you some very good starting parameters for these settings because it first measures the atmospheric motion and then sets the Min Move accordingly. A really powerful part of the program, I have found..

Aggressiveness setting is usually around 60% +- 10. On a good night i can sometimes set it higher, but above 80% doesn't buy much.

As far as Algorithms, I have used all of them and find not much difference in performance.

On a very steady night I have consistently gotten below 0.15 arc sec rms on both axes. Sometimes below 0.1. On the poorest night my guiding is around 0.45 arc sec rms.

Here is a typical result on a good night (4 out of 5 seeing):



And here is a poor night when the seeing was 2 out of 5:




-----Original Message-----
From: wayneh9026@yahoo..com <mailto:wayneh9026@...> [ap-gto] <ap-gto@... <mailto:ap-gto@...>>
To: ap-gto <ap-gto@... <mailto:ap-gto@...>>
Sent: Mon, Sep 9, 2019 5:00 pm
Subject: [ap-gto] Guiding guidance for Mach2?

Rolando, any guidance on autoguiding for the Mach2, given it’s absolute encoders? Such as settings for PHD2?

Thanks,

Wayne

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Posted by: wayneh9026@... <mailto:wayneh9026@...>
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MACH1 and 1100GTO

matt brown
 

Hi All,

 

I’m looking for some advice on mounts, specifically MACH2 and 1100GTO.

 

I am a beginning imager.  I image at home and would roll the mount, tripod, etc. fully assembled out of the garage whenever I image and use a RAPAS for polar alignment.  I don’t want to add a computer to the setup. I have a MGEN autoguider but would prefer to not guide.  I plan on controlling the mount through a tablet or smartphone.

 

I’m not after world class images nor would I be collecting scientific data. Either mount would carry the imaging train (currently a DSLR and Stowaway and work up to a C11 someday). I’m located in Iowa so seeing won’t be the greatest.

 

Would the absolute encoders on the MACH2 be worth the additional cost for this situation?  After reading about absolute encoders it seems they are most beneficial to advanced imagers or amateurs actually doing science.


Thanks,

matt


Re: Guiding guidance for Mach2?

Roland Christen
 

Hi Terri,
I'm not quite sure what your question is. If you have a mount that tracks at 0.1 arc sec rms like my first chart, then you have an excellent mount. If 0.6 arc sec rms meets your needs, then again you have the mount already for your application.
Where the Mach2 comes in is at the precision level where the system can be controlled to 0.1 arc sec pk via commands by external software. 0.6 rms sounds low but in reality the peak excursions will generally be 5 times that, around 3 arc sec pk-pk. That works ok for short focus instruments of around 500mm, but falls way short when using longer scopes that have inherent high resolution.

The original question was how to set up PHD2 for guiding with this mount. The simple answer is to use 2 sec or longer guide exposures so that a good guide star centroid can be calculated. Shorter exposures are not recommended, even in great seeing conditions. The rest I explained in my previous post.

Rolando

-----Original Message-----
From: Terri Zittritsch theresamarie11@... [ap-gto] <ap-gto@...>
To: chris1011@... [ap-gto] <ap-gto@...>
Sent: Tue, Sep 10, 2019 11:04 am
Subject: Re: [ap-gto] Guiding guidance for Mach2?

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Hi Rolando,I’ve thought about this a bit now, and I know chasing the seeing can be counter-productive when doing astrophotography.     If you have a mount that should be tracking at .25 arc-sec or less, and if the seeing is poor and causing you to make mount corrections of arc-seconds, isn’t this being counter productive?    Now of course I’m assuming perfect polar alignment which is hard to have especially if you’re always portable like me, and every night is different.   But I do use a polar camera/solver that seems to do well, and even with my Atlas can get .6 arc sec tracking with PHD and a 400mm guide scope  around the zenith (+-30 degrees) and have a chart like your first one (maybe not quite so pretty).  As I get towards the horizons all bets seem to be off and the atmosphere takes over and my excursions get much bigger (like your second chart only larger excursions).    
I’m just trying to wrap my head around making all of these large corrections (on your poor seeing night example) and what the encoders are doing for you in this case versus just very precise mechanicals (like A-P has always had).   This looks very much like what I deal with constantly with my atlas and as most nights don’t have great seeing.    All you really want to correct for, is any long term drift due to poor polar alignment or RA speed inaccuracy.     I’m probably not understanding something here.

Terri






On Sep 9, 2019, at 7:50 PM, chris1011@... [ap-gto] <ap-gto@...> wrote:

Trying again.
Rolando


-----Original Message-----
From: chris1011 <chris1011@...>
To: ap-gto <ap-gto@...>
Sent: Mon, Sep 9, 2019 5:46 pm
Subject: Re: [ap-gto] Guiding guidance for Mach2?

I have been guiding with 2 to 5 second exposures using PHD2. 2 sec for guiding on a calm night, up to 5 sec on a night of unsteady air. If you expose for less than 2 seconds, especially on a poor seeing night, you should dial in at least a 2 second delay between exposures. Otherwise the guide star is going to be jumping around a lot because the guide program is going to try to chase the seeing. I have tried as fast as 0.2 sec exposures with no delays, but the guiding is not great. At that exposure level the star's centroid will never stay still even on a good seeing night..

I set my Min Move according to what the atmospheric motion is that night. On a good seeing night it can be as low as 0.1 arc sec.. On a poor night I have it set to around 0.35 arc sec. If you use the Guide assistance, it will give you some very good starting parameters for these settings because it first measures the atmospheric motion and then sets the Min Move accordingly. A really powerful part of the program, I have found..

Aggressiveness setting is usually around 60% +- 10. On a good night i can sometimes set it higher, but above 80% doesn't buy much. 

As far as Algorithms, I have used all of them and find not much difference in performance. 

On a very steady night I have consistently gotten below 0.15 arc sec rms on both axes. Sometimes below 0.1. On the poorest night my guiding is around 0.45 arc sec rms.

Here is a typical result on a good night (4 out of 5 seeing):

And here is a poor night when the seeing was 2 out of 5:


-----Original Message-----
From: wayneh9026@yahoo..com [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Mon, Sep 9, 2019 5:00 pm
Subject: [ap-gto] Guiding guidance for Mach2?

Rolando, any guidance on autoguiding for the Mach2, given it’s absolute encoders? Such as settings for PHD2?

Thanks,

Wayne 

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Posted by: wayneh9026@...
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Re: Adapting CGEM Tripod to Mach1?

Worsel
 


Re: Guiding guidance for Mach2?

Terri Zittritsch
 

Hi Rolando,
I’ve thought about this a bit now, and I know chasing the seeing can be counter-productive when doing astrophotography. If you have a mount that should be tracking at .25 arc-sec or less, and if the seeing is poor and causing you to make mount corrections of arc-seconds, isn’t this being counter productive? Now of course I’m assuming perfect polar alignment which is hard to have especially if you’re always portable like me, and every night is different. But I do use a polar camera/solver that seems to do well, and even with my Atlas can get .6 arc sec tracking with PHD and a 400mm guide scope around the zenith (+-30 degrees) and have a chart like your first one (maybe not quite so pretty). As I get towards the horizons all bets seem to be off and the atmosphere takes over and my excursions get much bigger (like your second chart only larger excursions).

I’m just trying to wrap my head around making all of these large corrections (on your poor seeing night example) and what the encoders are doing for you in this case versus just very precise mechanicals (like A-P has always had). This looks very much like what I deal with constantly with my atlas and as most nights don’t have great seeing. All you really want to correct for, is any long term drift due to poor polar alignment or RA speed inaccuracy. I’m probably not understanding something here.


Terri

On Sep 9, 2019, at 7:50 PM, chris1011@... [ap-gto] <ap-gto@...> wrote:


Trying again.

Rolando


-----Original Message-----
From: chris1011 <chris1011@... <mailto:chris1011@...>>
To: ap-gto <ap-gto@... <mailto:ap-gto@...>>
Sent: Mon, Sep 9, 2019 5:46 pm
Subject: Re: [ap-gto] Guiding guidance for Mach2?

I have been guiding with 2 to 5 second exposures using PHD2. 2 sec for guiding on a calm night, up to 5 sec on a night of unsteady air. If you expose for less than 2 seconds, especially on a poor seeing night, you should dial in at least a 2 second delay between exposures. Otherwise the guide star is going to be jumping around a lot because the guide program is going to try to chase the seeing. I have tried as fast as 0.2 sec exposures with no delays, but the guiding is not great. At that exposure level the star's centroid will never stay still even on a good seeing night..

I set my Min Move according to what the atmospheric motion is that night. On a good seeing night it can be as low as 0.1 arc sec.. On a poor night I have it set to around 0.35 arc sec. If you use the Guide assistance, it will give you some very good starting parameters for these settings because it first measures the atmospheric motion and then sets the Min Move accordingly. A really powerful part of the program, I have found..

Aggressiveness setting is usually around 60% +- 10. On a good night i can sometimes set it higher, but above 80% doesn't buy much.

As far as Algorithms, I have used all of them and find not much difference in performance.

On a very steady night I have consistently gotten below 0.15 arc sec rms on both axes. Sometimes below 0.1. On the poorest night my guiding is around 0.45 arc sec rms.

Here is a typical result on a good night (4 out of 5 seeing):



And here is a poor night when the seeing was 2 out of 5:




-----Original Message-----
From: wayneh9026@... <mailto:wayneh9026@...> [ap-gto] <ap-gto@... <mailto:ap-gto@...>>
To: ap-gto <ap-gto@... <mailto:ap-gto@...>>
Sent: Mon, Sep 9, 2019 5:00 pm
Subject: [ap-gto] Guiding guidance for Mach2?

Rolando, any guidance on autoguiding for the Mach2, given it’s absolute encoders? Such as settings for PHD2?

Thanks,

Wayne

------------------------------------
Posted by: wayneh9026@... <mailto:wayneh9026@...>
------------------------------------

To UNSUBSCRIBE, or for general information on the ap-gto list
see http://groups.yahoo.com/group/ap-gto
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Re: Adapting CGEM Tripod to Mach1?

Geert
 

You probably need the ADATRI adapter, there is a hole pattern drawing somewhere in the AP website.

Geert Vdbulcke
Belgium

Op ma 9 sep. 2019 22:32 schreef wayneh9026@... [ap-gto] <ap-gto@...>:

 

I am selling my Mach1 to a friend who has a Celestron CGEM tripod. Is there a way to adapt that tripod to a Mach1? Wondering if anyone here has done that.

Wayne


Re: Images attachment instead of inline

Yves Laroche