Topics

Create a PEM curve with a camera?

David Enck
 

Hello All, This may be a silly question, but can I use an ASI 290 mini guide camera (2.9 pixel size) through my guide scope (162 mm focal length) to create a PEM curve for my AP1100  when the day comes? Or should  it be through the   main scope.  It is a  Meade lx850 14 inch SCT..  Thinking the guide scope would avoid any mirror shift and such.. My main imaging  camera is a Canon T2i.. 

Thank you,  David

Stuart
 

Hey David, I'm sure you're right to be wondering about the guide scope approach. Have you used this guide scope / main scope together before and confirmed there is no flexure? If you haven't I'd be worried that you'll build a PEC curve for the guide scope only. 


On Wed, 20 May 2020 at 20:06, <davidenck@...> wrote:
Hello All, This may be a silly question, but can I use an ASI 290 mini guide camera (2.9 pixel size) through my guide scope (162 mm focal length) to create a PEM curve for my AP1100  when the day comes? Or should  it be through the   main scope.  It is a  Meade lx850 14 inch SCT..  Thinking the guide scope would avoid any mirror shift and such.. My main imaging  camera is a Canon T2i.. 

Thank you,  David


--

Stuart
http://www.astrofoto.ca/stuartheggie/

uncarollo2 <chris1011@aol.com>
 

I think so if you have a good pixel scale.

Rolando



-----Original Message-----
To: main@ap-gto.groups.io
Sent: Wed, May 20, 2020 7:06 pm
Subject: [ap-gto] Create a PEM curve with a camera?

Hello All, This may be a silly question, but can I use an ASI 290 mini guide camera (2.9 pixel size) through my guide scope (162 mm focal length) to create a PEM curve for my AP1100  when the day comes? Or should  it be through the   main scope.  It is a  Meade lx850 14 inch SCT..  Thinking the guide scope would avoid any mirror shift and such.. My main imaging  camera is a Canon T2i.. 

Thank you,  David

Bill Long
 

Should work fine, IIRC Ray has a special version of PHD just for PEMPro usage.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Stuart <stuart.j.heggie@...>
Sent: Wednesday, May 20, 2020 5:08 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Create a PEM curve with a camera?
 
Hey David, I'm sure you're right to be wondering about the guide scope approach. Have you used this guide scope / main scope together before and confirmed there is no flexure? If you haven't I'd be worried that you'll build a PEC curve for the guide scope only. 


On Wed, 20 May 2020 at 20:06, <davidenck@...> wrote:
Hello All, This may be a silly question, but can I use an ASI 290 mini guide camera (2.9 pixel size) through my guide scope (162 mm focal length) to create a PEM curve for my AP1100  when the day comes? Or should  it be through the   main scope.  It is a  Meade lx850 14 inch SCT..  Thinking the guide scope would avoid any mirror shift and such.. My main imaging  camera is a Canon T2i.. 

Thank you,  David


--

Stuart
http://www.astrofoto.ca/stuartheggie/

uncarollo2 <chris1011@aol.com>
 

The PE curve will apply to the mount, and has no bearing on what happens to the main scope flexure. By definition the PE curve cannot store flexure and making a PE curve automatically throws out any flexure component because it is not periodic.

Rolando


-----Original Message-----
From: Stuart <stuart.j.heggie@...>
To: main@ap-gto.groups.io
Sent: Wed, May 20, 2020 7:08 pm
Subject: Re: [ap-gto] Create a PEM curve with a camera?

Hey David, I'm sure you're right to be wondering about the guide scope approach. Have you used this guide scope / main scope together before and confirmed there is no flexure? If you haven't I'd be worried that you'll build a PEC curve for the guide scope only. 


On Wed, 20 May 2020 at 20:06, <davidenck@...> wrote:
Hello All, This may be a silly question, but can I use an ASI 290 mini guide camera (2.9 pixel size) through my guide scope (162 mm focal length) to create a PEM curve for my AP1100  when the day comes? Or should  it be through the   main scope.  It is a  Meade lx850 14 inch SCT..  Thinking the guide scope would avoid any mirror shift and such.. My main imaging  camera is a Canon T2i.. 

Thank you,  David

--

Stuart
http://www.astrofoto.ca/stuartheggie/

David Enck
 

Ok, great!  Thanks all for the information.  

David 

On May 20, 2020, at 5:18 PM, uncarollo2 <chris1011@...> via groups.io <chris1011@...> wrote:


The PE curve will apply to the mount, and has no bearing on what happens to the main scope flexure. By definition the PE curve cannot store flexure and making a PE curve automatically throws out any flexure component because it is not periodic.

Rolando


-----Original Message-----
From: Stuart <stuart.j.heggie@...>
To: main@ap-gto.groups.io
Sent: Wed, May 20, 2020 7:08 pm
Subject: Re: [ap-gto] Create a PEM curve with a camera?

Hey David, I'm sure you're right to be wondering about the guide scope approach. Have you used this guide scope / main scope together before and confirmed there is no flexure? If you haven't I'd be worried that you'll build a PEC curve for the guide scope only. 


On Wed, 20 May 2020 at 20:06, <davidenck@...> wrote:
Hello All, This may be a silly question, but can I use an ASI 290 mini guide camera (2.9 pixel size) through my guide scope (162 mm focal length) to create a PEM curve for my AP1100  when the day comes? Or should  it be through the   main scope.  It is a  Meade lx850 14 inch SCT..  Thinking the guide scope would avoid any mirror shift and such.. My main imaging  camera is a Canon T2i.. 

Thank you,  David

--

Stuart
http://www.astrofoto.ca/stuartheggie/

 

Generally people build PEC using their main scope, provided it's 0.5"/pix or less resolution. 



On Wed, May 20, 2020 at 6:29 PM David Enck <davidenck@...> wrote:
Ok, great!  Thanks all for the information.  

David 

On May 20, 2020, at 5:18 PM, uncarollo2 <chris1011@...> via groups.io <chris1011=aol.com@groups.io> wrote:


The PE curve will apply to the mount, and has no bearing on what happens to the main scope flexure. By definition the PE curve cannot store flexure and making a PE curve automatically throws out any flexure component because it is not periodic.

Rolando


-----Original Message-----
From: Stuart <stuart.j.heggie@...>
To: main@ap-gto.groups.io
Sent: Wed, May 20, 2020 7:08 pm
Subject: Re: [ap-gto] Create a PEM curve with a camera?

Hey David, I'm sure you're right to be wondering about the guide scope approach. Have you used this guide scope / main scope together before and confirmed there is no flexure? If you haven't I'd be worried that you'll build a PEC curve for the guide scope only. 


On Wed, 20 May 2020 at 20:06, <davidenck@...> wrote:
Hello All, This may be a silly question, but can I use an ASI 290 mini guide camera (2.9 pixel size) through my guide scope (162 mm focal length) to create a PEM curve for my AP1100  when the day comes? Or should  it be through the   main scope.  It is a  Meade lx850 14 inch SCT..  Thinking the guide scope would avoid any mirror shift and such.. My main imaging  camera is a Canon T2i.. 

Thank you,  David

--

Stuart
http://www.astrofoto.ca/stuartheggie/



--
Brian 



Brian Valente