Date   

Re: time zone and daylight savings

Geert
 

Vincent, just use UT time, so you never have to adjust for summer and wintertime, just a little calculation in your mind,simple.

Geert Vdbulcke
Belgium

Op do 28 mei 2020 om 19:02 schreef vincent.visonneau <v.visonneau@...>:

Hi

I woulk like to know what are the good time zone for my location, i live in west of france (Latitude : 47.15 north, Longitude : -1.4167) so west of the meridian...

I dont' understand what i must choose, daylight 1 or 0, which time zone and else, hope someone can help me.

Regards

Vincent


Re: Mach2 Unguided testing continues

Roland Christen
 

PHD can record the star centroid and you can watch the drift to see if you have a good model or not.

Rolando



-----Original Message-----
From: Dean Jacobsen <deanjacobsen@...>
To: main@ap-gto.groups.io
Sent: Thu, May 28, 2020 11:55 am
Subject: Re: [ap-gto] Mach2 Unguided testing continues

On Thu, May 28, 2020 at 09:38 AM, uncarollo2 <chris1011@...> wrote:
Why not? You can effectively turn guiding off in PHD by dialing in a large MinMove such as 20. Then basically the mount gets no guide corrections and can merrily track at the custom rate without interruption.
 
Rolando
... and yet another great option.  PHD2 is essentially sitting there idling away until a dither command is issued.
 
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 


Re: Mach2 Unguided testing continues

Dean Jacobsen
 

On Thu, May 28, 2020 at 09:35 AM, uncarollo2 <chris1011@...> wrote:
Right now we have not integrated plate solving, but this may be added in the future to make the cycle faster. Remember, this is just a quick way to achieve unguided imaging for an object that you wish to image all night long. Doesn't require super perfect polar alignment, although you want to be close to prevent field rotation.
Assume that the mount will be taken down and then set up for each use.

So, when using the keypad quick method, what happens after a meridian flip?

Will I need to re-do it again? ... or would doing the automated APCC full sky model be the best approach?
 
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 


Re: Mach2 Unguided testing continues

 

UPDATE:

i poked around on settling with direct mount a bit, the settle at parameter is kind of irrelevant as the amount will always be 0

however you can use the settle time and set if to a few seconds if you want your mount to settle after being nudged a certain amount of time. It sounds like 2-5 seconds is what is used there 

On Thu, May 28, 2020 at 10:00 AM Dean Jacobsen <deanjacobsen@...> wrote:
On Thu, May 28, 2020 at 09:42 AM, Brian Valente wrote:
i've used Direct Mount for unguided and it works great for dithering. you don't even need PHD at that point
Linda & Brian,

I am assuming that you also set the "settle at" parameter to 0.0 pixels?
 
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 



--
Brian 



Brian Valente


Re: Mach2 Unguided testing continues

Linda Thomas
 

I don’t have any experience using it so I might be wrong. But, I think the pixel value for settling is ignored and it just waits the settle time if you have that turned on.

On May 28, 2020, at 1:02 PM, Brian Valente <bvalente@...> wrote:

I don't believe settle has any impact since there is no guide star to settle on

but if you go the other route of using PHD, i would set the settle extremely high, like 5 pixels for 0 seconds, so essentially it disables it



On Thu, May 28, 2020 at 10:00 AM Dean Jacobsen <deanjacobsen@...> wrote:
On Thu, May 28, 2020 at 09:42 AM, Brian Valente wrote:
i've used Direct Mount for unguided and it works great for dithering. you don't even need PHD at that point
Linda & Brian, 

I am assuming that you also set the "settle at" parameter to 0.0 pixels?
 
-- 
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/ 
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 




-- 
Brian 



Brian Valente


Re: Mach2 Unguided testing continues

 

I don't believe settle has any impact since there is no guide star to settle on

but if you go the other route of using PHD, i would set the settle extremely high, like 5 pixels for 0 seconds, so essentially it disables it



On Thu, May 28, 2020 at 10:00 AM Dean Jacobsen <deanjacobsen@...> wrote:
On Thu, May 28, 2020 at 09:42 AM, Brian Valente wrote:
i've used Direct Mount for unguided and it works great for dithering. you don't even need PHD at that point
Linda & Brian,

I am assuming that you also set the "settle at" parameter to 0.0 pixels?
 
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 



--
Brian 



Brian Valente


time zone and daylight savings

vincent.visonneau
 

Hi

I woulk like to know what are the good time zone for my location, i live in west of france (Latitude : 47.15 north, Longitude : -1.4167) so west of the meridian...

I dont' understand what i must choose, daylight 1 or 0, which time zone and else, hope someone can help me.

Regards

Vincent


Re: Mach2 Unguided testing continues

Dean Jacobsen
 

On Thu, May 28, 2020 at 09:42 AM, Brian Valente wrote:
i've used Direct Mount for unguided and it works great for dithering. you don't even need PHD at that point
Linda & Brian,

I am assuming that you also set the "settle at" parameter to 0.0 pixels?
 
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 


Re: APCC Standard v1.8.2.0 and APCC Pro v1.8.2.1

Leon
 

Thanks for the insight, I went there and adjusted settings, this will be better. Thanks again. Leon


On May 27, 2020, at 6:57 PM, Worsel via groups.io <bryancashion@...> wrote:

Leon

Anyway, that's my question.. thanks. SO what I usually get hung up is at initial start up, I go to park 2 then turn on the scope, then pull up APCC, then connect, then I go to park screen and try to figure out what to do, So I'm parked now, do I unpark first, of course , then if so what tab, etc.......I'm usually OK when I'm closing up shop and go to park 2 and then park there. then shut down every thing. Any help or short cuts or understanding this a little better I would appreciate.

While I defer to A-P and Ray Gralak, I think you may be overworking this.

If you have set got everything set in Settings-> Edit Initial Mount Settings along with the AP Driver, then you should be able to startup APCC and be ready to slew to a target.  When you finish, you can just power down the mount; although I choose to Park 4 due to observatory roof clearance.

Bryan


Re: Mach2 Unguided testing continues

Dean Jacobsen
 

On Thu, May 28, 2020 at 09:38 AM, uncarollo2 <chris1011@...> wrote:
Why not? You can effectively turn guiding off in PHD by dialing in a large MinMove such as 20. Then basically the mount gets no guide corrections and can merrily track at the custom rate without interruption.
 
Rolando
... and yet another great option.  PHD2 is essentially sitting there idling away until a dither command is issued.
 
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 


Re: Mach2 Unguided testing continues

 

>>> In your SGP equipment profile, change it from PHD to Direct Mount Guider. Configure how much you want to dither and set your settling time and you should be good to go. You can dither but no need for guiding.

i've used Direct Mount for unguided and it works great for dithering. you don't even need PHD at that point

On Thu, May 28, 2020 at 9:28 AM Linda Thomas <linda@...> wrote:
Dean,

In your SGP equipment profile, change it from PHD to Direct Mount Guider. Configure how much you want to dither and set your settling time and you should be good to go. You can dither but no need for guiding.

Linda

On May 28, 2020, at 12:17 PM, Dean Jacobsen <deanjacobsen@...> wrote:

On Thu, May 28, 2020 at 08:08 AM, uncarollo2 <chris1011@...> wrote:
You can dither all you want. That does not affect the custom rates that are calculated and applied to follow the actual sky motion above you.
Think of it this way: If you have Sidereal rate set, but it is slightly too fast and causes stars to streak in a time exposure, you could theoretically slow the rate down so that it matches the motion of the stars that you are imaging. Dither moves the next frame over a few pixels but does not change that tracking rate that you have set. The next exposure will still have round stars but they will be offset slightly from the previous one. That's how dither works - it has nothing to do with the tracking rate.
 
Rolando
 Sure, no problem, I am up to speed with you on that.  It is the implementation with the image capture software that I haven't got a handle on yet.  PHD2 and SGP coordinate to dither between images based on the parameters that I dial in.  So, will SGP implement a random "dither" movement of the frame on its own without having PHD2 actually guiding?  That I don't know yet.
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 



--
Brian 



Brian Valente


Re: Mach2 Unguided testing continues

Roland Christen
 


So, will SGP implement a random "dither" movement of the frame on its own without having PHD2 actually guiding? 
Why not? You can effectively turn guiding off in PHD by dialing in a large MinMove such as 20. Then basically the mount gets no guide corrections and can merrily track at the custom rate without interruption.

Rolando


-----Original Message-----
From: Dean Jacobsen <deanjacobsen@...>
To: main@ap-gto.groups.io
Sent: Thu, May 28, 2020 11:17 am
Subject: Re: [ap-gto] Mach2 Unguided testing continues

On Thu, May 28, 2020 at 08:08 AM, uncarollo2 <chris1011@...> wrote:
You can dither all you want. That does not affect the custom rates that are calculated and applied to follow the actual sky motion above you.
Think of it this way: If you have Sidereal rate set, but it is slightly too fast and causes stars to streak in a time exposure, you could theoretically slow the rate down so that it matches the motion of the stars that you are imaging. Dither moves the next frame over a few pixels but does not change that tracking rate that you have set. The next exposure will still have round stars but they will be offset slightly from the previous one. That's how dither works - it has nothing to do with the tracking rate.
 
Rolando
 Sure, no problem, I am up to speed with you on that.  It is the implementation with the image capture software that I haven't got a handle on yet.  PHD2 and SGP coordinate to dither between images based on the parameters that I dial in.  So, will SGP implement a random "dither" movement of the frame on its own without having PHD2 actually guiding?  That I don't know yet.
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 


Re: Mach2 Unguided testing continues

Roland Christen
 

Right now we have not integrated plate solving, but this may be added in the future to make the cycle faster. Remember, this is just a quick way to achieve unguided imaging for an object that you wish to image all night long. Doesn't require super perfect polar alignment, although you want to be close to prevent field rotation.

If your goal is to capture exposures, unguided of many objects over the course of a night, then you are better off doing an automated full sky model via APCC Pro and using the more advanced capabilities of that program. It's really quite nice - a hand's off modeling program that creates an all-sky model without manual input. Can be done once for a permanent setup and used from then on every night as long as you don't change the setup.

Rolando



-----Original Message-----
From: Donald Rudny <mkea13800@...>
To: main@ap-gto.groups.io
Sent: Thu, May 28, 2020 10:56 am
Subject: Re: [ap-gto] Mach2 Unguided testing continues

Thank you, Rolando.  That sounds great!  I like fast and accurate.  It’s simple, too.  I was thinking that there may have been some plate solving involved, but this is much better. 

Don

Don Rudny


On May 28, 2020, at 4:30 AM, uncarollo2 <chris1011@...> via groups.io <chris1011@...> wrote:


The idea is to center a star on a crosshair. When the star is centered via the keypad buttons you simply press Enter on the keypad and the position is recorded in the mount. The crosshair can be an eyepiece or you can use the crosshair function of your camera imaging software.
I have used MaximDL and my CCD camera to place the star on the crosshair. I have also used a QHY 5 -II camera which has video mode and a crosshair in place of an eyepiece. It's fast and accurate.

Rolando



-----Original Message-----
From: Donald Rudny <mkea13800@...>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 10:23 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

Hi All,

After following this thread, I am still unsure of how this is done.  Sounds like a revolutionary system.  I have an AP1100 with CP4, so I think I just need to upgrade the CP4  firmware and buy an upgraded keypad.  It sounds like there needs to be a camera input.  How is that done?  I didn’t think there was any input into the keypad for a camera input.  Is APCC involved at all?  Hope someone can explain in simple terms.

Thanks

Don

Don Rudny


On May 27, 2020, at 4:01 PM, Bruce Donzanti <donza2735@...> wrote:


Thank you/ good to know it will work on my AP1100 and Mach 1

Appreciate the follow up information 




On May 27, 2020, at 9:35 PM, uncarollo2 <chris1011@...> via groups.io <chris1011@...> wrote:


I did a bunch of testing this spring with my 175 refractor/1600AE mount in our Hawaii observatory. Was able to get easily 20 minute exposures for many hours on the same object until it went too low in the west. never got around to processing them since my goal was not pretty images but data on tracking accuracy, etc. I also did some preliminary work last year at the AP observatory with my 17" astrograph and 1600AE mount.

So yes, the program will work with any of our mounts, not just the Mach2.

Rolando



-----Original Message-----
From: Bruce Donzanti <donza2735@...>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 8:22 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

Understood and I appreciate the apology.  I look forward to learning more about this as I prefer to abandon my finicky PHD guiding.  


On May 27, 2020, at 9:12 PM, uncarollo2 <chris1011@...> via groups.io <chris1011@...> wrote:


It wasn't meant that way, and i apologize if it came across that way. This routine requires the keypad and cannot be easily done any other way. It would probably take me another year to turn it into something that could be used on a laptop or other device. And I don't have that much life left in me anymore ;^))

Rolando



-----Original Message-----
From: Bruce Donzanti <donza2735@...>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 8:05 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

ok- I don't doubt that; your efforts and ingenuity is greatly appreciated; no reason to get snippy; a simple no would have sufficed to someone who bought two of your mounts or the suggestion that Robert presented to me about an extension to the keypad

On Wed, May 27, 2020 at 9:01 PM uncarollo2 <chris1011@...> via groups.io <chris1011=aol.com@groups.io> wrote:
It's a keypad routine. We spent a great deal of time developing this program for the keypad. I can't even count the number of hours that the three of us put into development (Charles - keypad software, Mike - CP4/5 software, and me the conductor of it all).

Rolando



-----Original Message-----
From: Bruce Donzanti <donza2735@...>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 7:42 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

Roland 

My CP4 is about 8 ft above my laptop desk in my observatory.   So, not sure the hand controller will reach that far down and I do not want to purchase APCC.  Does that mean I am out of luck or is there an app just to mimic the hand controller routine from the CP4 to the laptop?

Bruce

On Wed, May 27, 2020 at 8:29 PM uncarollo2 <chris1011@...> via groups.io <chris1011=aol.com@groups.io> wrote:
Yes, this is a hand controller routine.

Rolando



-----Original Message-----
From: Worsel via groups.io <bryancashion=yahoo.com@groups.io>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 7:04 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

Roland

Encoders are NOT required then...just a CP4 with updated firmware.  I recognize this is not yet available.

I also recall an earlier thread indicating the APCC Pro would be able to do the same, if a hand controller is not used.

Bryan


Re: Mach2 Unguided testing continues

Dean Jacobsen
 

On Thu, May 28, 2020 at 09:28 AM, Linda Thomas wrote:
In your SGP equipment profile, change it from PHD to Direct Mount Guider. Configure how much you want to dither and set your settling time and you should be good to go. You can dither but no need for guiding.
 
HOW COOL IS THAT!  Thank you very much Linda.  Awesome! 
 
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 


Re: Mach2 Unguided testing continues

Linda Thomas
 

Dean,

In your SGP equipment profile, change it from PHD to Direct Mount Guider. Configure how much you want to dither and set your settling time and you should be good to go. You can dither but no need for guiding.

Linda

On May 28, 2020, at 12:17 PM, Dean Jacobsen <deanjacobsen@...> wrote:

On Thu, May 28, 2020 at 08:08 AM, uncarollo2 <chris1011@...> wrote:
You can dither all you want. That does not affect the custom rates that are calculated and applied to follow the actual sky motion above you.
Think of it this way: If you have Sidereal rate set, but it is slightly too fast and causes stars to streak in a time exposure, you could theoretically slow the rate down so that it matches the motion of the stars that you are imaging. Dither moves the next frame over a few pixels but does not change that tracking rate that you have set. The next exposure will still have round stars but they will be offset slightly from the previous one. That's how dither works - it has nothing to do with the tracking rate.
 
Rolando
 Sure, no problem, I am up to speed with you on that.  It is the implementation with the image capture software that I haven't got a handle on yet.  PHD2 and SGP coordinate to dither between images based on the parameters that I dial in.  So, will SGP implement a random "dither" movement of the frame on its own without having PHD2 actually guiding?  That I don't know yet.
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 


Re: Mach2 Unguided testing continues

Dean Jacobsen
 

On Thu, May 28, 2020 at 08:08 AM, uncarollo2 <chris1011@...> wrote:
You can dither all you want. That does not affect the custom rates that are calculated and applied to follow the actual sky motion above you.
Think of it this way: If you have Sidereal rate set, but it is slightly too fast and causes stars to streak in a time exposure, you could theoretically slow the rate down so that it matches the motion of the stars that you are imaging. Dither moves the next frame over a few pixels but does not change that tracking rate that you have set. The next exposure will still have round stars but they will be offset slightly from the previous one. That's how dither works - it has nothing to do with the tracking rate.
 
Rolando
 Sure, no problem, I am up to speed with you on that.  It is the implementation with the image capture software that I haven't got a handle on yet.  PHD2 and SGP coordinate to dither between images based on the parameters that I dial in.  So, will SGP implement a random "dither" movement of the frame on its own without having PHD2 actually guiding?  That I don't know yet.
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
Astrobin - https://www.astrobin.com/users/deanjacobsen/ 


Re: Mach2 Unguided testing continues

Donald Rudny
 

Thank you, Rolando.  That sounds great!  I like fast and accurate.  It’s simple, too.  I was thinking that there may have been some plate solving involved, but this is much better. 

Don

Don Rudny


On May 28, 2020, at 4:30 AM, uncarollo2 <chris1011@...> via groups.io <chris1011@...> wrote:


The idea is to center a star on a crosshair. When the star is centered via the keypad buttons you simply press Enter on the keypad and the position is recorded in the mount. The crosshair can be an eyepiece or you can use the crosshair function of your camera imaging software.
I have used MaximDL and my CCD camera to place the star on the crosshair. I have also used a QHY 5 -II camera which has video mode and a crosshair in place of an eyepiece. It's fast and accurate.

Rolando



-----Original Message-----
From: Donald Rudny <mkea13800@...>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 10:23 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

Hi All,

After following this thread, I am still unsure of how this is done.  Sounds like a revolutionary system.  I have an AP1100 with CP4, so I think I just need to upgrade the CP4  firmware and buy an upgraded keypad.  It sounds like there needs to be a camera input.  How is that done?  I didn’t think there was any input into the keypad for a camera input.  Is APCC involved at all?  Hope someone can explain in simple terms.

Thanks

Don

Don Rudny


On May 27, 2020, at 4:01 PM, Bruce Donzanti <donza2735@...> wrote:


Thank you/ good to know it will work on my AP1100 and Mach 1

Appreciate the follow up information 




On May 27, 2020, at 9:35 PM, uncarollo2 <chris1011@...> via groups.io <chris1011@...> wrote:


I did a bunch of testing this spring with my 175 refractor/1600AE mount in our Hawaii observatory. Was able to get easily 20 minute exposures for many hours on the same object until it went too low in the west. never got around to processing them since my goal was not pretty images but data on tracking accuracy, etc. I also did some preliminary work last year at the AP observatory with my 17" astrograph and 1600AE mount.

So yes, the program will work with any of our mounts, not just the Mach2.

Rolando



-----Original Message-----
From: Bruce Donzanti <donza2735@...>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 8:22 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

Understood and I appreciate the apology.  I look forward to learning more about this as I prefer to abandon my finicky PHD guiding.  


On May 27, 2020, at 9:12 PM, uncarollo2 <chris1011@...> via groups.io <chris1011@...> wrote:


It wasn't meant that way, and i apologize if it came across that way. This routine requires the keypad and cannot be easily done any other way. It would probably take me another year to turn it into something that could be used on a laptop or other device. And I don't have that much life left in me anymore ;^))

Rolando



-----Original Message-----
From: Bruce Donzanti <donza2735@...>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 8:05 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

ok- I don't doubt that; your efforts and ingenuity is greatly appreciated; no reason to get snippy; a simple no would have sufficed to someone who bought two of your mounts or the suggestion that Robert presented to me about an extension to the keypad

On Wed, May 27, 2020 at 9:01 PM uncarollo2 <chris1011@...> via groups.io <chris1011=aol.com@groups.io> wrote:
It's a keypad routine. We spent a great deal of time developing this program for the keypad. I can't even count the number of hours that the three of us put into development (Charles - keypad software, Mike - CP4/5 software, and me the conductor of it all).

Rolando



-----Original Message-----
From: Bruce Donzanti <donza2735@...>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 7:42 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

Roland 

My CP4 is about 8 ft above my laptop desk in my observatory.   So, not sure the hand controller will reach that far down and I do not want to purchase APCC.  Does that mean I am out of luck or is there an app just to mimic the hand controller routine from the CP4 to the laptop?

Bruce

On Wed, May 27, 2020 at 8:29 PM uncarollo2 <chris1011@...> via groups.io <chris1011=aol.com@groups.io> wrote:
Yes, this is a hand controller routine.

Rolando



-----Original Message-----
From: Worsel via groups.io <bryancashion=yahoo.com@groups.io>
To: main@ap-gto.groups.io
Sent: Wed, May 27, 2020 7:04 pm
Subject: Re: [ap-gto] Mach2 Unguided testing continues

Roland

Encoders are NOT required then...just a CP4 with updated firmware.  I recognize this is not yet available.

I also recall an earlier thread indicating the APCC Pro would be able to do the same, if a hand controller is not used.

Bryan


Re: Mach2 Unguided testing continues

Roland Christen
 


I haven't figured out yet how I could take advantage of this and still be able to dither frames.
You can dither all you want. That does not affect the custom rates that are calculated and applied to follow the actual sky motion above you.
Think of it this way: If you have Sidereal rate set, but it is slightly too fast and causes stars to streak in a time exposure, you could theoretically slow the rate down so that it matches the motion of the stars that you are imaging. Dither moves the next frame over a few pixels but does not change that tracking rate that you have set. The next exposure will still have round stars but they will be offset slightly from the previous one. That's how dither works - it has nothing to do with the tracking rate.

Rolando


-----Original Message-----
From: Dean Jacobsen <deanjacobsen@...>
To: main@ap-gto.groups.io
Sent: Thu, May 28, 2020 9:40 am
Subject: Re: [ap-gto] Mach2 Unguided testing continues

On Wed, May 27, 2020 at 01:15 PM, uncarollo2 <chris1011@...> wrote:
Below is a 15 minute UNGUIDED exposure I took last night with the Mach2 mount, purposely NOT polar aligned, off to the point where RA and Dec were drifting at 16 arc sec/hr and 88arcsec/hr respectively. I took a single 5 min drift measurement at the beginning of the exposure and used that to set the custom tracking rates for the axes (all done automatically in the keypad). It was good for the next hour of unguided imaging. A second and third drift measurement was added for 3 more hours, but clouds moved in.
 
With a good model the accuracy is better, in my opinion, than guiding with PHD2 or MaximDL. There is no jumping around, back and forth pushing and pulling of the axes according to momentary guide star positions and sky scintillation. It's a smooth motion, very accurate tracking under precise encoder control. This is with a 160EDF refractor of 1200mm focal length at .9 arc sec per pixel image scale.
 
The drift model resides in the mount controller, so actually doesn't need a laptop to store the data. The drift measurement can be done with a consumer digital camera, and then that camera can be used all night to gather images without ever having any guider attached.
 
Roland
Very impressive... amazing actually.  I am really looking forward to hearing more about this.  It is definitely something I could use.

I am among those who have cameras that require that I dither my frames.  I haven't figured out yet how I could take advantage of this and still be able to dither frames.
 
--
Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
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Re: Mach2 Unguided testing continues

ernie.mastroianni@...
 

Wow.


Re: Mach2 Unguided testing continues

Dean Jacobsen
 

On Wed, May 27, 2020 at 01:15 PM, uncarollo2 <chris1011@...> wrote:
Below is a 15 minute UNGUIDED exposure I took last night with the Mach2 mount, purposely NOT polar aligned, off to the point where RA and Dec were drifting at 16 arc sec/hr and 88arcsec/hr respectively. I took a single 5 min drift measurement at the beginning of the exposure and used that to set the custom tracking rates for the axes (all done automatically in the keypad). It was good for the next hour of unguided imaging. A second and third drift measurement was added for 3 more hours, but clouds moved in.
 
With a good model the accuracy is better, in my opinion, than guiding with PHD2 or MaximDL. There is no jumping around, back and forth pushing and pulling of the axes according to momentary guide star positions and sky scintillation. It's a smooth motion, very accurate tracking under precise encoder control. This is with a 160EDF refractor of 1200mm focal length at .9 arc sec per pixel image scale.
 
The drift model resides in the mount controller, so actually doesn't need a laptop to store the data. The drift measurement can be done with a consumer digital camera, and then that camera can be used all night to gather images without ever having any guider attached.
 
Roland
Very impressive... amazing actually.  I am really looking forward to hearing more about this.  It is definitely something I could use.

I am among those who have cameras that require that I dither my frames.  I haven't figured out yet how I could take advantage of this and still be able to dither frames.
 
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Dean Jacobsen
http://astrophoto.net/wp/ 
Image Gallery - http://astrophoto.net/wp/image-gallery/
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