Date   

Mach2 Guide rate and question about gear meshing.

Micheal Fields Jr
 

What is the recommended guide rate setting?  My experience with premium mounts is that you reduce the guide rate.  The other mount I am using recommends .20 or .25 and I've been pretty happy with that.  

I think I saw somewhere the recommended with the Mach2 is 1.0x?  

But maybe your experience is different and you have a different value. I am using the latest nightly PHD2 with multi star guiding.


Next question is about gear meshing.  Specifically the RA.   I had rain predicted for today so I brought my gear inside and set it up in my kitchen so I could work on my camera spacing with a new precise parts adapter that came in the mail yesterday.  While I was carrying the mount into the house the saddle plate was up against my tummy and I could feel something that felt loose.  When I set it back on the tripod and bolted everything down tight, I  could wiggle the saddle and feel something click/clack .  I then followed the movement by eye and could see the entire RA had some movement.  The alignment marks for RA showed a bit of movement.   I didn't notice this before.  Now if I hold on to the OTA and wiggle it, I can hear it click/clack as it moves.  The weight is far under capacity with a C11 and a one shot color camera.  No filter wheels or rotators etc.    Here is a short video showing what I am experiencing.   What is interesting is that when making a model I was noticing some results that I thought were very strange depending on what side of the meridian it was  on but I assumed it was the fact I focus with my primary mirror so it moves.  However guiding was less than amazing too but again I had an excuse which was clouds moving in and that messes with the  guide stars.   So please take a look and tell me if this is normal.  Thanks!   Note: if you turn your volume up or use headphones you can hear it too.  https://youtu.be/JnhhFXc-uFw


Re: How long for UNGUIDED imaging with non AE mounts?

Worsel
 

As Ray notes, it depends...

Following is likely TMI!

For my 200 point model, it took 88'.  This is based on the time delta between first and last image, which is all captured in the model file (*.PNT) in C:/Program Data/AstroPhyscis/APPCC/Models (if you do not change the default folder).  The actual time is a bit longer to initialize SGP and APPM and load the model after.

About 25" to take a 5" image (19 M full-frame), plate solve, slew to next position, 2" settle time.  This can vary, mostly with the slew time.  I use SGP to take the image and plate-solve either with ASTAP or a local install of Astrometry.net.  ASTAP is much faster, but does not always solve.  AN is slower, but has never failed, if I set it up correctly.  Fairly fast PC.

If you go back through threads from last 6 months or so, you will find a discussion of doing localized sub-models in the areas you plan to image on a given night.  A valid approach, but open to discussion as to any time savings.  I recall Roland using a technique where he used a filter (H-alpha ?) during the model build that allowed him to start taking images for the model long before it was dark enough to take long-exposure images.

Bryan


Re: APPM pointing model using different cameras

Sam Saeed
 

Thank you for confirming. 

Sam




On Thursday, February 11, 2021, 9:40 PM, Xentex <michael@...> wrote:

You shouldn't have to change your model.


Re: How long for UNGUIDED imaging with non AE mounts?

Ray Gralak
 

So how long does it take to create a 200 point model?
That depends somewhat on image download time and plate solve time. Faster downloads will reduce time. A faster computer will usually plate-solve faster.

Typically it takes about 2-3 points/minute, so probably in the range of 65 to 100 minutes. If the setup is not moved or changed the model can last for months.

-Ray Gralak
Author of PEMPro
Author of APCC (Astro-Physics Command Center): https://www.astro-physics.com/apcc-pro
Author of Astro-Physics V2 ASCOM Driver: https://www.siriusimaging.com/apdriver

-----Original Message-----
From: main@ap-gto.groups.io [mailto:main@ap-gto.groups.io] On Behalf Of astro@dinoworld.com.au
Sent: Friday, February 12, 2021 12:20 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] How long for UNGUIDED imaging with non AE mounts?

On Fri, Feb 12, 2021 at 12:19 PM, Worsel wrote:


Bob

I have a 200 point model for a non-AE 1100 (PEM enabled) with a 2500 mm scope. I have been able to
image (0.54 a-s/pxl) unguided for 15 minutes, but not consistently. With a 700 mm scope, I think you could easily
do the same and more consistently than me.


Bryan

Thanks Bryan

So how long does it take to create a 200 point model?


Re: How long for UNGUIDED imaging with non AE mounts?

Bob
 

On Fri, Feb 12, 2021 at 12:19 PM, Worsel wrote:
Bob

I have a 200 point model for a non-AE 1100 (PEM enabled) with a 2500 mm scope. I have been able to image (0.54 a-s/pxl) unguided for 15 minutes, but not consistently.  With a 700 mm scope, I think you could easily do the same and more consistently than me.


Bryan
Thanks Bryan

So how long does it take to create a 200 point model?


Re: APPM pointing model using different cameras

Xentex
 

You shouldn't have to change your model.


Re: How long for UNGUIDED imaging with non AE mounts?

Worsel
 

Bob

I have a 200 point model for a non-AE 1100 (PEM enabled) with a 2500 mm scope. I have been able to image (0.54 a-s/pxl) unguided for 15 minutes, but not consistently.  With a 700 mm scope, I think you could easily do the same and more consistently than me.


Bryan


Re: How long for UNGUIDED imaging with non AE mounts?

Bob
 

On Thu, Feb 11, 2021 at 10:20 PM, Peter Nagy wrote:
Bob,

With or without pointing model using APCC Pro?

Peter 
Hi Peter

With a pointing model. I would assume several minutes would be achievable? How large would the model need to be?

Thanks
Bob


Re: Counterweight Shaft Case

Steve C. Mitchell, Sr., O.D.
 

What the hell are you doing bringing common sense to the party!
The perfect, simple, cost effective solution to the problem! Brilliant!
Steve 8>)

-----Original Message-----
From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Jeffc
Sent: Tuesday, February 9, 2021 8:21 PM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Counterweight Shaft Case

Here’s my awesome counterweight shaft transport case. This is for an AP1200 CW shaft, but I also have a very similar one for the shorter AP1100 shaft.
The case you see here is specially designed to prevent rolling around in the vehicle, and has been reinforced in the appropriate areas of the structure.
This has served me very very well since 2005 and has been to many star parties, public programs , and countless imaging sessions.
I give it 4 stars rating… knocking off a star as the cover needs minor work with some gaffers tape.


Re: How long for UNGUIDED imaging with non AE mounts?

Roland Christen
 


I can expect to achieve good unguided images with exposures in the tens of minutes? Maybe even up to 1 hour?
Probably not. I was doing unguided imaging with an encoder mount. I apologize if I misled anyone.
A mount that does not have shaft encoders is open loop and is at the mercy of the periodic error that is produced by the gearbox. One can minimize that error using PEM but that does not guarantee that it will track to sub-arc sec levels for an hour.

Rolando


-----Original Message-----
From: astro@...
To: main@ap-gto.groups.io
Sent: Thu, Feb 11, 2021 2:01 am
Subject: Re: [ap-gto] How long for UNGUIDED imaging with non AE mounts?

On Tue, Feb 9, 2021 at 11:15 PM, Roland Christen wrote:
I have gone up to an hour with 1000mm FL and 5.4 micron pixel camera.

--
Roland Christen
Astro-Physics
First, excuse me for asking for clarification/confirmation of what you just stated. My excuse is I am a virgin with AP gear.

So I have a gto1100 (hopefully soon) without Encoders. All other things being equal, and at moderate focal lengths, I can expect to achieve good unguided images with exposures in the tens of minutes? Maybe even up to 1 hour?

Cheers
Bob

--
Roland Christen
Astro-Physics


Re: How long for UNGUIDED imaging with non AE mounts?

Peter Nagy
 

Bob,

With or without pointing model using APCC Pro?

Peter 


Re: How long for UNGUIDED imaging with non AE mounts?

Bob
 

On Tue, Feb 9, 2021 at 11:15 PM, Roland Christen wrote:
I have gone up to an hour with 1000mm FL and 5.4 micron pixel camera.

--
Roland Christen
Astro-Physics
First, excuse me for asking for clarification/confirmation of what you just stated. My excuse is I am a virgin with AP gear.

So I have a gto1100 (hopefully soon) without Encoders. All other things being equal, and at moderate focal lengths, I can expect to achieve good unguided images with exposures in the tens of minutes? Maybe even up to 1 hour?

Cheers
Bob


APPM pointing model using different cameras

Sam Saeed
 

As per Roland a year ago answering one of my questions regarding APPM and camera rotation between sessions:

 

Quoting Roland:

(That is correct. The camera does not do anything as far as mount functions. It's like an eyepiece with a crosshair. You can rotate the crosshair all you want, it has no effect on the mount tracking rates.)

 

 

I just changed my main camera. The model that I currently have using the previous camera is practically close to perfection. I’m curious if I need to redo the model with the new camera as resolution has changed. But based on the above statement, I don’t have too.

 

Please correct me if I’m wrong.

 

 

Thanks

 

Sam Saeed

https://www.decanstars.com


Re: First light for a new camera

Don Anderson
 

Great job Dean! 

Don Anderson


On Wednesday, February 10, 2021, 11:19:50 a.m. MST, Dean Jacobsen <deanjacobsen@...> wrote:


Here is the final iteration:

https://www.astrobin.com/full/0ffdnz/E/

The full res version is viewable by clicking on the button at the upper right corner.  

I really like the amount of detail that can be seen in the Bok globules/dark nebula considering I was using a 4” refractor.
--
Dean Jacobsen
http://astrophoto.net/wp/
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/ 
Amateur Radio Call Sign - W6DBJ


Re: Factory PEC curve, how is it generated?

skester@...
 

Thank you Roland and Christopher.  Encoder measurement is the obvious choice in hindsight.


Re: Factory PEC curve, how is it generated?

Roland Christen
 

A precision encoder is attached to the RA axis and the resultant PE error is measured using software similar to PEMPro. We do about 5 cycles for each mount (takes about 1/2 hour for that measurement). The curve is calculated and downloaded into the CP and the error is measured again with PEM turned ON. The resultant curve is evaluated and if it's good, the mount goes thru the final testing stages.

Rolando



-----Original Message-----
From: skester@...
To: main@ap-gto.groups.io
Sent: Wed, Feb 10, 2021 12:49 pm
Subject: [ap-gto] Factory PEC curve, how is it generated?

This question is simply to satisfy my curiosity.  To create the factory installed PEC curve I assume each mount must be tested and track a star like source moving at sidereal rate for several worm gear cycles.  Doing this on a real star under the night sky would seem out of the question as it would require many clear nights and much time/effort to do for each mount produced.  That would seem to leave an artificial star that moves at a simulated sidereal rate on a test bench?  Or is there another method I haven't thought of, perhaps using encoders?

Thanks,
Scott
 

--
Roland Christen
Astro-Physics


Re: First light for a new camera

Dean Jacobsen
 

On Wed, Feb 10, 2021 at 10:39 AM, Roland Christen wrote:
Looks good. What is the pixel size binned 2x2?
Yes, this was with the 4.63um 2x2 binned pixel configuration.  Gain 120 and 240s exposures taken from my very light polluted back yard.
 
--
Dean Jacobsen
http://astrophoto.net/wp/
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/ 
Amateur Radio Call Sign - W6DBJ


Re: Factory PEC curve, how is it generated?

Christopher Erickson
 

My guess is a custom bench top jig with an absolute encoder.

-Christopher Erickson
Observatory engineer
Waikoloa, HI 96738
www.summitkinetics.com
   

On Wed, Feb 10, 2021, 8:49 AM <skester@...> wrote:
This question is simply to satisfy my curiosity.  To create the factory installed PEC curve I assume each mount must be tested and track a star like source moving at sidereal rate for several worm gear cycles.  Doing this on a real star under the night sky would seem out of the question as it would require many clear nights and much time/effort to do for each mount produced.  That would seem to leave an artificial star that moves at a simulated sidereal rate on a test bench?  Or is there another method I haven't thought of, perhaps using encoders?

Thanks,
Scott
 


Factory PEC curve, how is it generated?

skester@...
 

This question is simply to satisfy my curiosity.  To create the factory installed PEC curve I assume each mount must be tested and track a star like source moving at sidereal rate for several worm gear cycles.  Doing this on a real star under the night sky would seem out of the question as it would require many clear nights and much time/effort to do for each mount produced.  That would seem to leave an artificial star that moves at a simulated sidereal rate on a test bench?  Or is there another method I haven't thought of, perhaps using encoders?

Thanks,
Scott
 


Re: First light for a new camera

Bill Long
 

Thats the 4.63um mode (14 bit) on the camera. Bin 1x1 on the camera is 2.3um pixels (but 12 bit). It is kind of like two cameras in one in a way. 

Specs:




From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Wednesday, February 10, 2021 10:39 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] First light for a new camera
 
Looks good. What is the pixel size binned 2x2?

Roland



-----Original Message-----
From: Dean Jacobsen <deanjacobsen@...>
To: main@ap-gto.groups.io
Sent: Wed, Feb 10, 2021 12:19 pm
Subject: Re: [ap-gto] First light for a new camera

Here is the final iteration:

https://www.astrobin.com/full/0ffdnz/E/

The full res version is viewable by clicking on the button at the upper right corner.  

I really like the amount of detail that can be seen in the Bok globules/dark nebula considering I was using a 4” refractor.
--
Dean Jacobsen
http://astrophoto.net/wp/
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/ 
Amateur Radio Call Sign - W6DBJ

--
Roland Christen
Astro-Physics

6901 - 6920 of 83105