Date   

Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Roland Christen
 

If you have a PA error that means the guide star will continually move away from the center crosshair, even when the guide program sends a full move command to bring it back. But that's only half the story. During the exposure the guide star moves a certain amount, lets say 2 arc sec in a 5 second guide exposure. The guide exposure results in a calculated centroid position that is actually only 1 arc sec from the crosshair center. The reason for that is that the guide star starts from zero at the beginning of the exposure and ends up at 2 arc sec error at the end. The average position for that 5 sec exposure is half that distance. So now the mount gets a move command of 1 arc sec while the star is already off by 2. The result is that the guide star is always off the crosshair center. And then the user has to decide that either the mount is not fully responding, or that the guide software is in error. I like to keep my drift in RA and Dec down below 1 arc sec per 5 minutes at the zenith for best guiding results. On a night of decent seeing I always get rms guide values below 0.2 arc sec.

Rolando

-----Original Message-----
From: Cheng-Yang Tan cytan299@... [ap-gto] <ap-gto@...>
To: chris1011@... [ap-gto]
Sent: Sat, May 11, 2019 2:15 pm
Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



I also pushed aggression up to 90% right before stopping to redo PA, but it still wasn't enough. That was when I decided to redo the PA because of the errors.

cytan

On Saturday, May 11, 2019, 1:59:28 PM CDT, chris1011@... [ap-gto] wrote:


 

I looked more carefully at the log and there *is* movement. I'm just surprised that the RA error was not corrected. it's at 70% aggressiveness for the Hysteresis algorithm.
70% aggress means that for a 1 arc sec error the mount is commanded to move only 0.7 arc sec, so at that setting the mount will not fully correct the error. Another thing that happens is that the guide star may have moved further in the wrong direction on the next guide exposure, so it may look like the mount did not respond. However, the mount axis probably did move by the requested amount, but the requested move just wasn't enough to bring the star back.

Rolando


-----Original Message-----
From: Cheng-Yang Tan cytan299@... [ap-gto]
To: chris1011@... [ap-gto]
Sent: Sat, May 11, 2019 1:24 pm
Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi Rolando 
  I looked more carefully at the log and there *is* movement. I'm just surprised that the RA error was not corrected. it's at 70% aggressiveness for the Hysteresis algorithm.

1x guide rate. I've uploaded the APCC log: 


for Ray to have a look at. I'll also query the PHD group as well. Let's see what they say.

cytan

On Saturday, May 11, 2019, 11:18:51 AM CDT, chris1011@... [ap-gto] wrote:


 

I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360.
Get one of our heavy duty Losmandy tripods, made for the 1100 (in my opinion the i-Optron pier is sub-standard for this mount).
          
           "The no RA response is probably not a PHD2 problem."

Not sure what this means. There was no movement of the RA even though a move command was sent? Was a move command actually sent? RA does not have any delay since you are always tracking and the gears are always engaged, so any move command, no matter how small, always moves the star. Are you using 1x guide rate or something other?

Rolando


-----Original Message-----
From: cytan299@... [ap-gto]
To: ap-gto
Sent: Sat, May 11, 2019 10:22 am
Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi guys,
 
   Here's the results from last night's run (10 May 2019) with my AP1100AE. 
  

As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I think this algorithm works a lot better than Resist Switch for absolute encoder mounts.

The guide logs are attached.

The screen captures show what is going on:

calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2 frames looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA response to corrections.

no_RA_response.jpg: Zoomed in view.

redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging session, at 22:08 and 23:29. Very annoying)

The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?

overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC  aggression to 90% and minmov from 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is very good.

Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.



cytan










Re: New file uploaded to ap-gto

Roland Christen
 

Sounds like I need to do the same. Unfortunately we have clouds and rain for the foreseeable future.

Rolando



-----Original Message-----
From: sornborger@... [ap-gto]
To: ap-gto
Sent: Sat, May 11, 2019 2:12 pm
Subject: Re: [ap-gto] New file uploaded to ap-gto



I dumped using hysterisis over a year ago even before I purchased my 1100.  Always guides better with it set to zero for me.


Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Cheng-Yang Tan
 

I also pushed aggression up to 90% right before stopping to redo PA, but it still wasn't enough. That was when I decided to redo the PA because of the errors.

cytan

On Saturday, May 11, 2019, 1:59:28 PM CDT, chris1011@... [ap-gto] wrote:


 


I looked more carefully at the log and there *is* movement. I'm just surprised that the RA error was not corrected. it's at 70% aggressiveness for the Hysteresis algorithm.
70% aggress means that for a 1 arc sec error the mount is commanded to move only 0.7 arc sec, so at that setting the mount will not fully correct the error. Another thing that happens is that the guide star may have moved further in the wrong direction on the next guide exposure, so it may look like the mount did not respond. However, the mount axis probably did move by the requested amount, but the requested move just wasn't enough to bring the star back.

Rolando


-----Original Message-----
From: Cheng-Yang Tan cytan299@... [ap-gto]
To: chris1011@... [ap-gto]
Sent: Sat, May 11, 2019 1:24 pm
Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi Rolando 
  I looked more carefully at the log and there *is* movement. I'm just surprised that the RA error was not corrected. it's at 70% aggressiveness for the Hysteresis algorithm.

1x guide rate. I've uploaded the APCC log: 


for Ray to have a look at. I'll also query the PHD group as well. Let's see what they say.

cytan

On Saturday, May 11, 2019, 11:18:51 AM CDT, chris1011@... [ap-gto] wrote:


 

I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360.
Get one of our heavy duty Losmandy tripods, made for the 1100 (in my opinion the i-Optron pier is sub-standard for this mount).
          
           "The no RA response is probably not a PHD2 problem."

Not sure what this means. There was no movement of the RA even though a move command was sent? Was a move command actually sent? RA does not have any delay since you are always tracking and the gears are always engaged, so any move command, no matter how small, always moves the star. Are you using 1x guide rate or something other?

Rolando


-----Original Message-----
From: cytan299@... [ap-gto]
To: ap-gto
Sent: Sat, May 11, 2019 10:22 am
Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi guys,
 
   Here's the results from last night's run (10 May 2019) with my AP1100AE. 
  

As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I think this algorithm works a lot better than Resist Switch for absolute encoder mounts.

The guide logs are attached.

The screen captures show what is going on:

calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2 frames looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA response to corrections.

no_RA_response.jpg: Zoomed in view.

redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging session, at 22:08 and 23:29. Very annoying)

The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?

overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC  aggression to 90% and minmov from 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is very good.

Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.



cytan








Re: Mach 1 tracking problem

Roland Christen
 

Thanks for your thoughts.
Actually on the mounts section of CN it isn't too bad until we get into encoders. The issue with encoders is that this is something new and not well understood, so as a result there is a lot of bad info. The really interesting section is refractors, and there I cannot tell you how much misinfo there is - it's just breathtaking.

Rolando



-----Original Message-----
From: stelios_t@... [ap-gto]
To: ap-gto
Sent: Sat, May 11, 2019 1:59 pm
Subject: [ap-gto] Re: Mach 1 tracking problem



Roland, as a CN moderator, I can assure you we don't ban people for trying to clear up misconceptions. Yes, it is regrettable that a lot of misinformation and bad advice exists there, but that's the way of our present world. Blame the person who first said "everyone's entitled to their opinion"--the most destructive meme ever.

But on CN we do insist that *even if someone said something totally stupid*, and *even if someone refuses to take good advice but repeats the error he made*, people still should limit their posts to factual information and conceal their exasperation. Basically, take a couple of deep breaths and re-read post before hitting the send button--and in some cases, just don't hit that button. 

For someone's posting privileges to be curtailed, they must have made *repeated* aggressive comments, shown *repeated* exasperation, or *repeatedly* made disparaging personal remarks. Please note that this is our policy--we are not perfect, and please don't ask me to comment on any particular situation. 

The goal of the moderators is to keep the discussion civil, and the environment pleasant and welcoming--but the moderators are totally neutral as to the question of accuracy of comments. That is for the person reading to decide. A civil post that is 100% wrong is as allowable as a civil post that is 100% correct.

I might as well add my personal opinion, that you have many more supporters than detractors on CN. With good reason your products are much loved, and your service is often quoted as the best there is. 

Additionally, some of us with very high opinions of Astro-Physics, will sometimes post on CN first with an issue, because we simply don't want to waste AP's valuable time with what often is just a user "senior moment." 



Re: New file uploaded to ap-gto

sornborger@...
 

I dumped using hysterisis over a year ago even before I purchased my 1100.  Always guides better with it set to zero for me.


Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Cheng-Yang Tan
 

My guide rate is 1.00x

cytan

On Saturday, May 11, 2019, 1:55:50 PM CDT, chris1011@... [ap-gto] wrote:


 

Are you using 1x sidereal for guiding, or something less?

Rolando



-----Original Message-----
From: Cheng-Yang Tan cytan299@... [ap-gto]
To: 'Ray Gralak (Groups)' groups3@... [ap-gto]
Sent: Sat, May 11, 2019 1:21 pm
Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi Ray,
   I just uploaded the APCC log file to: 


There are no errors that I can see. The relevant portion is around 21:52 to 21:56.

Anyway, after examining the PHD log more carefully, I can say that the mount *is* responding in RA. However, it's not moving as aggressively as the error suggests. So I take back what I had said earlier: PHD2 cannot be ruled out yet. The Hysteresis algorithm for RA is, I believe, a well used algorithm for RA and I'm quite surprised that it's not doing what I'd expect. Or it's doing exactly as intended at 70% aggression.  I'll send my query to the PHD group to see what they say.

cytan



On Saturday, May 11, 2019, 11:20:02 AM CDT, 'Ray Gralak (Groups)' groups3@... [ap-gto] wrote:


 
> Simple, because I have a used mount. Perhaps you guys have seen this before like cabling etc.
>
> Have you seen this before?

Yes, if the driver is reporting communication errors. But that's still not the mount. That's your cable or USB/serial adapter, etc.

So, is the driver reporting communication errors?

-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: Saturday, May 11, 2019 9:08 AM
> To: ap-gto@...
> Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm
>
>
>
> Simple, because I have a used mount. Perhaps you guys have seen this before like cabling etc.
>
> Have you seen this before?
>
> cytan
>
>
>
>
>
>
> On Saturday, May 11, 2019, 11:01 AM, 'Ray Gralak (Groups)' groups3@... [ap-gto] > gto@...> wrote:
>
>
>
> > The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?
>
> Okay, I'll bite... why would you assume it's not a PHD2 problem?
>
> -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: Saturday, May 11, 2019 8:17 AM
> > To: ap-gto@...
> > Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm
> >
> >
> >
> > Hi guys,
> >
> >
> >
> > Here's the results from last night's run (10 May 2019) with my AP1100AE.
> >
> >
> >
> > https://groups.yahoo.com/neo/groups/ap-
> > gto/files/AP1100AE%20and%20PHD2%20DEC%20guiding%20with%20LowPass2%20algorithm/
> >
> >
> >
> >
> >
> > As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I
> think this
> > algorithm works a lot better than Resist Switch for absolute encoder mounts.
> >
> >
> >
> >
> > The guide logs are attached.
> >
> >
> >
> >
> > The screen captures show what is going on:
> >
> >
> >
> >
> > calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2
> frames
> > looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA
> response to
> > corrections.
> >
> >
> >
> >
> > no_RA_response.jpg: Zoomed in view.
> >
> >
> >
> >
> > redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my
> setup is not
> > holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging
> session, at
> > 22:08 and 23:29. Very annoying)
> >
> >
> >
> >
> > The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?
> >
> >
> >
> >
> > overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC aggression to 90% and
> minmov from
> > 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is
> very good.
> >
> >
> >
> >
> > Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > cytan
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
>




Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Roland Christen
 


The Losmandy HD Tripod is nice
It is definitely nice, extremely steady, and we have the right adapters for that tripod for the 1100. We can supply it for you.

Rolando


-----Original Message-----
From: Bill Long bill@... [ap-gto]
To: ap-gto@...
Sent: Sat, May 11, 2019 1:33 pm
Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



The Losmandy HD Tripod is nice, I use the model with the fold-in legs. Very sturdy. I added the 12" pier extension to it.


From: ap-gto@... on behalf of Cheng-Yang Tan cytan299@... [ap-gto]
Sent: Saturday, May 11, 2019 11:30 AM
To: ap-gto@...
Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm
 
 
P.S. I'm using the Tri-Pier 360 which is the bigger brother of the original Tri-pier. (https://www.ioptron.com/product-p/8037.htm)

Unfortunately, IMO, the tri-pier 360 is not very well designed. See my critique: 


I really can't stand the stupid feet of this pier. Plus there are other design problems.

I'll be looking at getting an ATS portable pier to replace the tri-pier 360. But not right now. The hole in my pocket after getting the AP1100AE is still too large :)

cytan

On Saturday, May 11, 2019, 11:18:51 AM CDT, chris1011@... [ap-gto] wrote:


 

I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360.
Get one of our heavy duty Losmandy tripods, made for the 1100 (in my opinion the i-Optron pier is sub-standard for this mount).
          
           "The no RA response is probably not a PHD2 problem."

Not sure what this means. There was no movement of the RA even though a move command was sent? Was a move command actually sent? RA does not have any delay since you are always tracking and the gears are always engaged, so any move command, no matter how small, always moves the star. Are you using 1x guide rate or something other?

Rolando


-----Original Message-----
From: cytan299@... [ap-gto]
To: ap-gto
Sent: Sat, May 11, 2019 10:22 am
Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi guys,
 
   Here's the results from last night's run (10 May 2019) with my AP1100AE. 
  

As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I think this algorithm works a lot better than Resist Switch for absolute encoder mounts.

The guide logs are attached.

The screen captures show what is going on:

calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2 frames looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA response to corrections.

no_RA_response.jpg: Zoomed in view.

redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging session, at 22:08 and 23:29. Very annoying)

The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?

overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC  aggression to 90% and minmov from 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is very good.

Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.



cytan








Re: Mach 1 tracking problem

Stelios
 

Roland, as a CN moderator, I can assure you we don't ban people for trying to clear up misconceptions. Yes, it is regrettable that a lot of misinformation and bad advice exists there, but that's the way of our present world. Blame the person who first said "everyone's entitled to their opinion"--the most destructive meme ever.

But on CN we do insist that *even if someone said something totally stupid*, and *even if someone refuses to take good advice but repeats the error he made*, people still should limit their posts to factual information and conceal their exasperation. Basically, take a couple of deep breaths and re-read post before hitting the send button--and in some cases, just don't hit that button. 

For someone's posting privileges to be curtailed, they must have made *repeated* aggressive comments, shown *repeated* exasperation, or *repeatedly* made disparaging personal remarks. Please note that this is our policy--we are not perfect, and please don't ask me to comment on any particular situation. 

The goal of the moderators is to keep the discussion civil, and the environment pleasant and welcoming--but the moderators are totally neutral as to the question of accuracy of comments. That is for the person reading to decide. A civil post that is 100% wrong is as allowable as a civil post that is 100% correct.

I might as well add my personal opinion, that you have many more supporters than detractors on CN. With good reason your products are much loved, and your service is often quoted as the best there is. 

Additionally, some of us with very high opinions of Astro-Physics, will sometimes post on CN first with an issue, because we simply don't want to waste AP's valuable time with what often is just a user "senior moment." 


Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

sornborger@...
 

+1 Losmandy HD Tripod.  It ain't pretty, but it's a beast of a foundation.

Rich


Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Roland Christen
 


I looked more carefully at the log and there *is* movement. I'm just surprised that the RA error was not corrected. it's at 70% aggressiveness for the Hysteresis algorithm.
70% aggress means that for a 1 arc sec error the mount is commanded to move only 0.7 arc sec, so at that setting the mount will not fully correct the error. Another thing that happens is that the guide star may have moved further in the wrong direction on the next guide exposure, so it may look like the mount did not respond. However, the mount axis probably did move by the requested amount, but the requested move just wasn't enough to bring the star back.

Rolando


-----Original Message-----
From: Cheng-Yang Tan cytan299@... [ap-gto]
To: chris1011@... [ap-gto]
Sent: Sat, May 11, 2019 1:24 pm
Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi Rolando 
  I looked more carefully at the log and there *is* movement. I'm just surprised that the RA error was not corrected. it's at 70% aggressiveness for the Hysteresis algorithm.

1x guide rate. I've uploaded the APCC log: 


for Ray to have a look at. I'll also query the PHD group as well. Let's see what they say.

cytan

On Saturday, May 11, 2019, 11:18:51 AM CDT, chris1011@... [ap-gto] wrote:


 

I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360.
Get one of our heavy duty Losmandy tripods, made for the 1100 (in my opinion the i-Optron pier is sub-standard for this mount).
          
           "The no RA response is probably not a PHD2 problem."

Not sure what this means. There was no movement of the RA even though a move command was sent? Was a move command actually sent? RA does not have any delay since you are always tracking and the gears are always engaged, so any move command, no matter how small, always moves the star. Are you using 1x guide rate or something other?

Rolando


-----Original Message-----
From: cytan299@... [ap-gto] To: ap-gto
Sent: Sat, May 11, 2019 10:22 am
Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi guys,
 
   Here's the results from last night's run (10 May 2019) with my AP1100AE. 
  

As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I think this algorithm works a lot better than Resist Switch for absolute encoder mounts.

The guide logs are attached.

The screen captures show what is going on:

calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2 frames looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA response to corrections.

no_RA_response.jpg: Zoomed in view.

redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging session, at 22:08 and 23:29. Very annoying)

The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?

overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC  aggression to 90% and minmov from 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is very good.

Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.



cytan








Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Roland Christen
 

Are you using 1x sidereal for guiding, or something less?

Rolando



-----Original Message-----
From: Cheng-Yang Tan cytan299@... [ap-gto]
To: 'Ray Gralak (Groups)' groups3@... [ap-gto]
Sent: Sat, May 11, 2019 1:21 pm
Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi Ray,
   I just uploaded the APCC log file to: 


There are no errors that I can see. The relevant portion is around 21:52 to 21:56.

Anyway, after examining the PHD log more carefully, I can say that the mount *is* responding in RA. However, it's not moving as aggressively as the error suggests. So I take back what I had said earlier: PHD2 cannot be ruled out yet. The Hysteresis algorithm for RA is, I believe, a well used algorithm for RA and I'm quite surprised that it's not doing what I'd expect. Or it's doing exactly as intended at 70% aggression.  I'll send my query to the PHD group to see what they say.

cytan



On Saturday, May 11, 2019, 11:20:02 AM CDT, 'Ray Gralak (Groups)' groups3@... [ap-gto] wrote:


 
> Simple, because I have a used mount. Perhaps you guys have seen this before like cabling etc.
>
> Have you seen this before?

Yes, if the driver is reporting communication errors. But that's still not the mount. That's your cable or USB/serial adapter, etc.

So, is the driver reporting communication errors?

-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: Saturday, May 11, 2019 9:08 AM
> To: ap-gto@...
> Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm
>
>
>
> Simple, because I have a used mount. Perhaps you guys have seen this before like cabling etc.
>
> Have you seen this before?
>
> cytan
>
>
>
>
>
>
> On Saturday, May 11, 2019, 11:01 AM, 'Ray Gralak (Groups)' groups3@... [ap-gto] > gto@...> wrote:
>
>
>
> > The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?
>
> Okay, I'll bite... why would you assume it's not a PHD2 problem?
>
> -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: Saturday, May 11, 2019 8:17 AM
> > To: ap-gto@...
> > Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm
> >
> >
> >
> > Hi guys,
> >
> >
> >
> > Here's the results from last night's run (10 May 2019) with my AP1100AE.
> >
> >
> >
> > https://groups.yahoo.com/neo/groups/ap-
> > gto/files/AP1100AE%20and%20PHD2%20DEC%20guiding%20with%20LowPass2%20algorithm/
> >
> >
> >
> >
> >
> > As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I
> think this
> > algorithm works a lot better than Resist Switch for absolute encoder mounts.
> >
> >
> >
> >
> > The guide logs are attached.
> >
> >
> >
> >
> > The screen captures show what is going on:
> >
> >
> >
> >
> > calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2
> frames
> > looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA
> response to
> > corrections.
> >
> >
> >
> >
> > no_RA_response.jpg: Zoomed in view.
> >
> >
> >
> >
> > redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my
> setup is not
> > holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging
> session, at
> > 22:08 and 23:29. Very annoying)
> >
> >
> >
> >
> > The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?
> >
> >
> >
> >
> > overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC aggression to 90% and
> minmov from
> > 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is
> very good.
> >
> >
> >
> >
> > Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > cytan
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
>




Re: New file uploaded to ap-gto

Cheng-Yang Tan
 

Thanks Doug! Another option to try which I will, for the RA errors. Gawd, I should really RTFM :) 

Unfortunately, there may not be an opportunity to test this option out within the next week if the weather forecasts are to be believed.

cytan

On Saturday, May 11, 2019, 1:36:36 PM CDT, tallman.doug@... [ap-gto] wrote:


 

Regarding Bill's earlier comment "There has got to be a way to set PHD2 to work similarly to your experience with MaximDL", I came across this while reading a few pages of Chris Woodhouse's "Astrophotography Manual" today:


[in PHD2] "The hysteresis function, with hysteresis set to 0, behaves similarly to Maxim DL's guiding algorithm." (p. 309)

This might be worth trying.

-Doug


---In ap-gto@..., wrote :

Adding Andy Glasso to the thread here. There has got to be a way to set PHD2 to work similarly to your experience with MaximDL.


From: ap-gto@... on behalf of chris1011@... [ap-gto]
Sent: Monday, May 6, 2019 7:00 PM
To: ap-gto@...
Subject: Re: [ap-gto] New file uploaded to ap-gto
 
 

Max move doesn't come into play for small corrections on the order of 1 arc sec.

Rolando



-----Original Message-----
From: Bill Long bill@... [ap-gto]
To: ap-gto@...
Sent: Mon, May 6, 2019 8:41 pm
Subject: Re: [ap-gto] New file uploaded to ap-gto



Hey Roland,

Did you try lowering the MxDEC value in PHD? That will allow you to change the maximum size of a correction, without changing the aggression. I use 2000 and have used 1500 in the past with good success. The default is 2500 and at 28% aggressiveness as you mentioned, it would only apply up to a 700 move. Maybe put the aggression back to 100% and set MxDEC to 1500?


From: ap-gto@... on behalf of chris1011@... [ap-gto]
Sent: Monday, May 6, 2019 6:27 PM
To: ap-gto@...
Subject: Re: [ap-gto] New file uploaded to ap-gto
 
 
Hi Cytan,

There is no way that the encoders have anything to do with causing Dec aggressiveness to behave this way. The encoders work perfectly with MaximDL at the proper settings of 100% aggressiveness.

And yes, you are getting the same instability as I was getting.

Rolando



-----Original Message-----
From: cytan299@... [ap-gto] To: ap-gto
Sent: Mon, May 6, 2019 7:59 pm
Subject: Re: [ap-gto] New file uploaded to ap-gto



Hi Rolando,
   I'm still experimenting with my AP1100AE with PHD2 settings and saw this on Saturday night. I'm glad that you may be seeing what I saw and I can confirm what you saw. Please see:


When I had DEC aggression set to 100%, the DEC behaviour is clearly very odd. Then I turned it off to see whether the seeing was that bad. Clearly not! I then set DEC aggression to 50% and it looked a lot better.

Perhaps its the absolute encoders and PHD2 DEC guiding not playing well together?

cytan





Re: New file uploaded to ap-gto

tallman.doug
 

Regarding Bill's earlier comment "There has got to be a way to set PHD2 to work similarly to your experience with MaximDL", I came across this while reading a few pages of Chris Woodhouse's "Astrophotography Manual" today:

[in PHD2] "The hysteresis function, with hysteresis set to 0, behaves similarly to Maxim DL's guiding algorithm." (p. 309)

This might be worth trying.

-Doug


---In ap-gto@..., <bill@...> wrote :

Adding Andy Glasso to the thread here. There has got to be a way to set PHD2 to work similarly to your experience with MaximDL.


From: ap-gto@... <ap-gto@...> on behalf of chris1011@... [ap-gto] <ap-gto@...>
Sent: Monday, May 6, 2019 7:00 PM
To: ap-gto@...
Subject: Re: [ap-gto] New file uploaded to ap-gto
 
 

Max move doesn't come into play for small corrections on the order of 1 arc sec.

Rolando



-----Original Message-----
From: Bill Long bill@... [ap-gto] <ap-gto@...>
To: ap-gto@... <ap-gto@...>
Sent: Mon, May 6, 2019 8:41 pm
Subject: Re: [ap-gto] New file uploaded to ap-gto



Hey Roland,

Did you try lowering the MxDEC value in PHD? That will allow you to change the maximum size of a correction, without changing the aggression. I use 2000 and have used 1500 in the past with good success. The default is 2500 and at 28% aggressiveness as you mentioned, it would only apply up to a 700 move. Maybe put the aggression back to 100% and set MxDEC to 1500?


From: ap-gto@... <ap-gto@...> on behalf of chris1011@... [ap-gto] <ap-gto@...>
Sent: Monday, May 6, 2019 6:27 PM
To: ap-gto@...
Subject: Re: [ap-gto] New file uploaded to ap-gto
 
 
Hi Cytan,

There is no way that the encoders have anything to do with causing Dec aggressiveness to behave this way. The encoders work perfectly with MaximDL at the proper settings of 100% aggressiveness.

And yes, you are getting the same instability as I was getting.

Rolando



-----Original Message-----
From: cytan299@... [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Mon, May 6, 2019 7:59 pm
Subject: Re: [ap-gto] New file uploaded to ap-gto



Hi Rolando,
   I'm still experimenting with my AP1100AE with PHD2 settings and saw this on Saturday night. I'm glad that you may be seeing what I saw and I can confirm what you saw. Please see:


When I had DEC aggression set to 100%, the DEC behaviour is clearly very odd. Then I turned it off to see whether the seeing was that bad. Clearly not! I then set DEC aggression to 50% and it looked a lot better.

Perhaps its the absolute encoders and PHD2 DEC guiding not playing well together?

cytan





Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Bill Long
 

The Losmandy HD Tripod is nice, I use the model with the fold-in legs. Very sturdy. I added the 12" pier extension to it.


From: ap-gto@... on behalf of Cheng-Yang Tan cytan299@... [ap-gto]
Sent: Saturday, May 11, 2019 11:30 AM
To: ap-gto@...
Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm
 
 

P.S. I'm using the Tri-Pier 360 which is the bigger brother of the original Tri-pier. (https://www.ioptron.com/product-p/8037.htm)

Unfortunately, IMO, the tri-pier 360 is not very well designed. See my critique: 


I really can't stand the stupid feet of this pier. Plus there are other design problems.

I'll be looking at getting an ATS portable pier to replace the tri-pier 360. But not right now. The hole in my pocket after getting the AP1100AE is still too large :)

cytan

On Saturday, May 11, 2019, 11:18:51 AM CDT, chris1011@... [ap-gto] wrote:


 


I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360.
Get one of our heavy duty Losmandy tripods, made for the 1100 (in my opinion the i-Optron pier is sub-standard for this mount).
          
           "The no RA response is probably not a PHD2 problem."

Not sure what this means. There was no movement of the RA even though a move command was sent? Was a move command actually sent? RA does not have any delay since you are always tracking and the gears are always engaged, so any move command, no matter how small, always moves the star. Are you using 1x guide rate or something other?

Rolando


-----Original Message-----
From: cytan299@... [ap-gto]
To: ap-gto
Sent: Sat, May 11, 2019 10:22 am
Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi guys,
 
   Here's the results from last night's run (10 May 2019) with my AP1100AE. 
  

As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I think this algorithm works a lot better than Resist Switch for absolute encoder mounts.

The guide logs are attached.

The screen captures show what is going on:

calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2 frames looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA response to corrections.

no_RA_response.jpg: Zoomed in view.

redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging session, at 22:08 and 23:29. Very annoying)

The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?

overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC  aggression to 90% and minmov from 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is very good.

Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.



cytan






Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Cheng-Yang Tan
 

P.S. I'm using the Tri-Pier 360 which is the bigger brother of the original Tri-pier. (https://www.ioptron.com/product-p/8037.htm)

Unfortunately, IMO, the tri-pier 360 is not very well designed. See my critique: 


I really can't stand the stupid feet of this pier. Plus there are other design problems.

I'll be looking at getting an ATS portable pier to replace the tri-pier 360. But not right now. The hole in my pocket after getting the AP1100AE is still too large :)

cytan

On Saturday, May 11, 2019, 11:18:51 AM CDT, chris1011@... [ap-gto] wrote:


 


I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360.
Get one of our heavy duty Losmandy tripods, made for the 1100 (in my opinion the i-Optron pier is sub-standard for this mount).
          
           "The no RA response is probably not a PHD2 problem."

Not sure what this means. There was no movement of the RA even though a move command was sent? Was a move command actually sent? RA does not have any delay since you are always tracking and the gears are always engaged, so any move command, no matter how small, always moves the star. Are you using 1x guide rate or something other?

Rolando


-----Original Message-----
From: cytan299@... [ap-gto]
To: ap-gto
Sent: Sat, May 11, 2019 10:22 am
Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi guys,
 
   Here's the results from last night's run (10 May 2019) with my AP1100AE. 
  

As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I think this algorithm works a lot better than Resist Switch for absolute encoder mounts.

The guide logs are attached.

The screen captures show what is going on:

calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2 frames looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA response to corrections.

no_RA_response.jpg: Zoomed in view.

redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging session, at 22:08 and 23:29. Very annoying)

The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?

overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC  aggression to 90% and minmov from 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is very good.

Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.



cytan






Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Cheng-Yang Tan
 

Hi Rolando 
  I looked more carefully at the log and there *is* movement. I'm just surprised that the RA error was not corrected. it's at 70% aggressiveness for the Hysteresis algorithm.

1x guide rate. I've uploaded the APCC log: 


for Ray to have a look at. I'll also query the PHD group as well. Let's see what they say.

cytan

On Saturday, May 11, 2019, 11:18:51 AM CDT, chris1011@... [ap-gto] wrote:


 


I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360.
Get one of our heavy duty Losmandy tripods, made for the 1100 (in my opinion the i-Optron pier is sub-standard for this mount).
          
           "The no RA response is probably not a PHD2 problem."

Not sure what this means. There was no movement of the RA even though a move command was sent? Was a move command actually sent? RA does not have any delay since you are always tracking and the gears are always engaged, so any move command, no matter how small, always moves the star. Are you using 1x guide rate or something other?

Rolando


-----Original Message-----
From: cytan299@... [ap-gto]
To: ap-gto
Sent: Sat, May 11, 2019 10:22 am
Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm



Hi guys,
 
   Here's the results from last night's run (10 May 2019) with my AP1100AE. 
  

As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I think this algorithm works a lot better than Resist Switch for absolute encoder mounts.

The guide logs are attached.

The screen captures show what is going on:

calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2 frames looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA response to corrections.

no_RA_response.jpg: Zoomed in view.

redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my setup is not holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging session, at 22:08 and 23:29. Very annoying)

The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?

overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC  aggression to 90% and minmov from 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is very good.

Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.



cytan






Re: AP1100AE using PHD2 LowPass2 DEC guiding algorithm

Cheng-Yang Tan
 

Hi Ray,
   I just uploaded the APCC log file to: 


There are no errors that I can see. The relevant portion is around 21:52 to 21:56.

Anyway, after examining the PHD log more carefully, I can say that the mount *is* responding in RA. However, it's not moving as aggressively as the error suggests. So I take back what I had said earlier: PHD2 cannot be ruled out yet. The Hysteresis algorithm for RA is, I believe, a well used algorithm for RA and I'm quite surprised that it's not doing what I'd expect. Or it's doing exactly as intended at 70% aggression.  I'll send my query to the PHD group to see what they say.

cytan



On Saturday, May 11, 2019, 11:20:02 AM CDT, 'Ray Gralak (Groups)' groups3@... [ap-gto] wrote:


 

> Simple, because I have a used mount. Perhaps you guys have seen this before like cabling etc.
>
> Have you seen this before?

Yes, if the driver is reporting communication errors. But that's still not the mount. That's your cable or USB/serial adapter, etc.

So, is the driver reporting communication errors?

-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: Saturday, May 11, 2019 9:08 AM
> To: ap-gto@...
> Subject: Re: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm
>
>
>
> Simple, because I have a used mount. Perhaps you guys have seen this before like cabling etc.
>
> Have you seen this before?
>
> cytan
>
>
>
>
>
>
> On Saturday, May 11, 2019, 11:01 AM, 'Ray Gralak (Groups)' groups3@... [ap-gto] > gto@...> wrote:
>
>
>
> > The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?
>
> Okay, I'll bite... why would you assume it's not a PHD2 problem?
>
> -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: Saturday, May 11, 2019 8:17 AM
> > To: ap-gto@...
> > Subject: [ap-gto] AP1100AE using PHD2 LowPass2 DEC guiding algorithm
> >
> >
> >
> > Hi guys,
> >
> >
> >
> > Here's the results from last night's run (10 May 2019) with my AP1100AE.
> >
> >
> >
> > https://groups.yahoo.com/neo/groups/ap-
> > gto/files/AP1100AE%20and%20PHD2%20DEC%20guiding%20with%20LowPass2%20algorithm/
> >
> >
> >
> >
> >
> > As recommended by the gurus at PHD2, I am using LowPass2 for the DEC guide algorithm. Overall, I
> think this
> > algorithm works a lot better than Resist Switch for absolute encoder mounts.
> >
> >
> >
> >
> > The guide logs are attached.
> >
> >
> >
> >
> > The screen captures show what is going on:
> >
> >
> >
> >
> > calibration.jpg: Calibration run with 0.5s exposure to get the parameters from Guide Assistant. The first 2
> frames
> > looks decent. But the third frame starting around 21:56 showed a weird problem that there is no RA
> response to
> > corrections.
> >
> >
> >
> >
> > no_RA_response.jpg: Zoomed in view.
> >
> >
> >
> >
> > redid_PA.jpg: I then redid my PA again and that seemed to fix the problem.(I think the reason why my
> setup is not
> > holding PA is probably from the rubber feet of the iOptron tripier 360. I redid PA twice during this imaging
> session, at
> > 22:08 and 23:29. Very annoying)
> >
> >
> >
> >
> > The no RA response is probably not a PHD2 problem. Can Roland or Ray comment on this?
> >
> >
> >
> >
> > overall_ok.jpg: Anyway, with the RA responding again and I upping my DEC aggression to 90% and
> minmov from
> > 0.2 (as recommended by guiding assistant) to 0.15, the guiding rms ~0.5 arcseconds which I think is
> very good.
> >
> >
> >
> >
> > Unfortunately, clouds rolled in 00:25 (11 May) so I couldn't measure guiding in DEC off.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > cytan
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
>


Re: New file uploaded to ap-gto

Bill Long
 

Yes Howard took care of me. 🙂


From: ap-gto@... <ap-gto@...> on behalf of Marj marj@... [ap-gto] <ap-gto@...>
Sent: Saturday, May 11, 2019 7:56 AM
To: ap-gto@...
Subject: RE: [ap-gto] New file uploaded to ap-gto
 
 

Bill,

 

Has your GTOCP4 been updated for the encoders? That is an essential step to the process.

 

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

 

From: ap-gto@... [mailto:ap-gto@...]
Sent: Friday, May 10, 2019 6:43 PM
To: ap-gto@...
Subject: Re: [ap-gto] New file uploaded to ap-gto

 

 

I will be able to test this tonight. Completely clear and the AE kit is installed. 🙂 

 


From: ap-gto@... <ap-gto@...> on behalf of Cheng-Yang Tan cytan299@... [ap-gto] <ap-gto@...>
Sent: Friday, May 10, 2019 2:25 PM
To: ap-gto@...
Subject: Re: [ap-gto] New file uploaded to ap-gto

 

 

I'll try it out tonight if there is a chance. Looks like partly cloudy though.

 

cytan

 

On Friday, May 10, 2019, 3:46:24 PM CDT, stephenjwinston@... [ap-gto] <ap-gto@...> wrote:

 

 

 

Update for those not following Cytan's thread on the Open PHD2 forum (Google Groups).

 

Google Groups

Google Groups allows you to create and participate in online forums and email-based groups with a rich experienc...

 

 

 

The PHD2 devs analyzed Cytan's logs and confirmed that the default Resist Switch algorithm is not the best fit for mounts with absolute encoders or minimal to no DEC backlash.

 

They suggest using the Hysterisis, Lowpass2 or Z-filter algorithms instead, and apparently will update a future version of PHD2 to default to one of those algorithms when a mount with encoders is detected.

 

Roland - hopefully you will get some clear skies over the next couple of nights and can let us know if you see better behavior using one of the other algorithms for DEC!

 

Steve


Re: Mach 1 tracking problem

Roland Christen
 

You raise an interesting point about vibes. Maybe it's an expression of frustration on my part and for that I apologize.

I've seen changes in the hobby from the days when it was mandatory for users to know much more about their equipment and how things actually work. In a lot of cases people built their own stuff, even the optics, and consequently had real working knowledge about how things worked. Everyone read S&T and Astronomy magazine, and they had frequent articles which went into depth on various aspects of the hobby. The articles were carefully researched and written by very knowledgeable people who actually knew their stuff. Many good books on our hobby were written and are still written but does anyone read books anymore?

Contrast that with what's happening today on the internet. Everyone gets to say their piece regardless if they know what they are talking about. The result is a helter skelter of stuff flying in all different directions, and sometimes if a false narrative is repeated by enough people it becomes truth. It is amazing how much misinformation there is on some CN posts, and every once in a while a real expert on the subject tries to help and gets banned in the process! I know several people that got banned for simply trying to clear up misconceptions. The thinking of those knowledgeable guys who are still around on CN is that you better be very gentle in your answers to people and never press your point lest you get moderated or outright banned.

That's not to say that the internet is not useful for finding out facts. There are still plenty of ways to get good info, but the great days of magazine editorial control of good information are over.

P.S. your mount issue is almost certainly that your PEM data has been inadvertently erased and thus you have a small periodic error that prevents you from getting round stars at your focal length.

Rolando



-----Original Message-----
From: donzantib@... [ap-gto]
To: ap-gto
Sent: Sat, May 11, 2019 12:10 pm
Subject: Re: [ap-gto] Re: Mach 1 tracking problem



Understood but I contacted George via email and he is trying to help and requested the 5 min exposure you looked at.  Probably better to call next time as things through email can sometimes move an issue along at a snails pace.  Also, It is not your long-winded explanations.  In fact, some of those are the best and incredibly helpful and yes, I understand you know this stuff better than most.  In fact, I expect that and that is why I am asking for help on your mount that I bought and was thinking of getting a heavier one for my observatory.   However, I sometimes get vibes from your responses like, boy, you are an idiot.  Well, I can do the same thing if you ask me questions about what I do in my profession.  And maybe the signals I picked up are misguided and if so, I apologize for that.  That is why I also asked on CNs, realizing the danger of getting advice from someone who knows even less than me.  

Anyway, I prefer to move on and a less learned for me: call AP first and take it from there.






Re: Mach 1 tracking problem

Bruce Donzanti
 

Got it - thank you 


On May 11, 2019, at 1:06 PM, chris1011@... [ap-gto] <ap-gto@...> wrote:

 


I think the intent was just to verify the drifting and to note if it was in RA.
Periodic error is NOT drift. The two things are quite different. Drift is a continuous motion in one direction which eventually moves the object completely out of the field of view.

Periodic error is simply a back and forth movement of the object (or star) over a distance of about 5 - 7 arc seconds. The trail of the star movement often has a brighter point at the beginning and end of the trail, just like your 5 minute image shows. This is very characteristic of periodic error, and is not characteristic of drift, where the star trail has no brightening anywhere along the path. Judging by the number of pixels in your posted image taken with your camera, I would estimate that your periodic error is somewhere in the 5 to 7 arc sec range and seems to be quire regular. This means that a simple re-doing of the PE curve and downloading it into the CP controller will get you back to where you were before.

Now here is what I think happened when you suddenly had this "drift". I'm betting a bowl of ice cream that somehow you inadvertently erased the PE curve in the mount memory during one of your setups and you actually have no compensating curve at all. That would explain why turning the PEM on does not change anything. Because there is nothing there in memory. PEMPro can dig out what's in memory, another very useful tool of that amazing program. If that's the case, then you can be assured that nothing has happened to the mount's mechanical integrity, and I can sleep peacefully for at least one night.

Rolando


-----Original Message-----
From: donzantib@... [ap-gto] <ap-gto@...>
To: ap-gto <ap-gto@...>
Sent: Sat, May 11, 2019 11:53 am
Subject: Re: [ap-gto] Re: Mach 1 tracking problem



Thank you for the in-depth and clear explanation of things to be aware of and check.  I did the 5 min at George's request.  I think the intent was just to verify the drifting and to note if it was in RA. DEC, or both.  In any event, I will press on and figure this out. 

I will call the office next week for the grease kit.  

Thanks again,
Bruce






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