Elephant Trunk, AP1100AE as a sleep aide


ap@CaptivePhotons.com
 

I suggest that the AP1100AE be submitted to the FDA for approval as a sleep aide. 

I tend to wake up in the week hours when my system is imaging, and roll over and unlock the phone and RDP in to check how things are going.  Last couple of nights the PHD2 log, which pops up first, had the first digit of a 1. That is a definite incentive to just go back to sleep and let it keep doing what it is doing.  Better than Ambien.  Almost as good as Bourbon.  :) 

I'm in that period here in Florida where it rains too much but there are a few nights open with really still air, but the wind has not picked up as it does during the actual dry season. 

I did finally find enough nights in between rain to finish off the elephant trunk (here "finish" could be defined as "got tired of collecting data" moreso than "definitely got enough data" -- but let's not split hairs). 

This is at 2800mm in RGB + SHO (all rolled together).  It has 30s RGB stars, the color is more from broadband mixed with the narrow band, and all the detail is from 36 hours of narrow band data (vs only 5.9 of BB for color).  No luminance, just synthetic luminance from narrow band.  I went through a rainbow of color variations and settled here.

Criticism and suggestions welcomed.

Full size version: https://www.astrobin.com/85ed5q/0/

Linwood

PS. If you submit to the FDA, will Medicare then pay for the mounts? 


Emilio J. Robau, P.E.
 

Linwood,

That is a fine image for a Florida summer.   Last night was actually quite nice.  This hurricane will usher in the change in weather.  I just hope it does not hit us.  Somewhat tired of Andres, Charlie, and Irma for sure.  Anyways, I am going to try tonight and should have tried last night.  The air was very still and the sky was reasonable.  However, I have to work to pay for my 1100 and in hopeful waiting for my 130 and 110.  Very nice image.  I am amazed you can get any photons at all.


Roland Christen
 

Some thoughts from the peanut gallery,

Although you may have clouds and rain, we here in the Midwest have both plus we are under the jet stream most of the time with lousy seeing. Last night as an example I was out testing scopes and software with seeing at an abysmal 3 arc sec FWHM with a scope that can produce 1.3 FWHM in good seeing.

So, having said that, your image is quite nice, and the RGB does add a bit of 3-D to it compared to a normal narrowband Hubble palette like this one that I took last year: https://www.astrobin.com/full/g0bpv3/C/

What struck me about yours was the extraordinary amount of time you spent shooting this object compared to mine: i.e. 42 hours of data versus 10 hrs. And you had the advantage of a new high-falutin' CMOS camera that's some 3 times faster than my lowly QSI 683 with the slooow 8300 Kodak chip. Interestingly, we both had very close to the same 0.4 degree field radius. Your chip also has nearly 4 times the area of my QSI 683. The 10" F6.3 can cover a full frame format of course, I just didn't have the camera at the time to image with it.

Sooo, I'm using a 10" F6.3 flat field Mak-astrograph, and I have always been wondering if it's the right thing to spend time making in production, seeing as the SCTs of this size are so cheap. Maybe an SCT with an F6.3 reducer would negate the need for this scope?

Rolando

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 1:18 pm
Subject: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

I suggest that the AP1100AE be submitted to the FDA for approval as a sleep aide. 

I tend to wake up in the week hours when my system is imaging, and roll over and unlock the phone and RDP in to check how things are going.  Last couple of nights the PHD2 log, which pops up first, had the first digit of a 1. That is a definite incentive to just go back to sleep and let it keep doing what it is doing.  Better than Ambien.  Almost as good as Bourbon.  :) 

I'm in that period here in Florida where it rains too much but there are a few nights open with really still air, but the wind has not picked up as it does during the actual dry season. 

I did finally find enough nights in between rain to finish off the elephant trunk (here "finish" could be defined as "got tired of collecting data" moreso than "definitely got enough data" -- but let's not split hairs). 

This is at 2800mm in RGB + SHO (all rolled together).  It has 30s RGB stars, the color is more from broadband mixed with the narrow band, and all the detail is from 36 hours of narrow band data (vs only 5.9 of BB for color).  No luminance, just synthetic luminance from narrow band.  I went through a rainbow of color variations and settled here.

Criticism and suggestions welcomed.

Full size version: https://www.astrobin.com/85ed5q/0/

Linwood

PS. If you submit to the FDA, will Medicare then pay for the mounts? 


--
Roland Christen
Astro-Physics


Peter Nagy
 

On Fri, Sep 23, 2022 at 11:18 AM, ap@... wrote:
Almost as good as Bourbon.  :) 
I prefer Scotch Whiskey. 😉 

Peter


Bill Long
 

SCTs aren't bad, but have a number of issues that prevent me from wanting to use one for deep sky imaging. They are slow, the reducers for them aren't very good, focusing can cause mirror flopping/shifting issues, bright stars can get a reflection on them or elsewhere in images, they don't have good cooling out of the box, etc.

To get one really up to snuff for high quality imaging takes a lot of work and extra money. Even then you still have some issues you just cannot fix unless you design and engineer your own solutions, like Dr Hayes did.

As for the viability of the Mak Cass f6.3 I think the design improvements you mentioned with permanent collimation, a high quality focuser, etc would be hard to pass up. Ultimately that would depend on the price I guess.

Bill



From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Friday, September 23, 2022 12:08 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 
Some thoughts from the peanut gallery,

Although you may have clouds and rain, we here in the Midwest have both plus we are under the jet stream most of the time with lousy seeing. Last night as an example I was out testing scopes and software with seeing at an abysmal 3 arc sec FWHM with a scope that can produce 1.3 FWHM in good seeing.

So, having said that, your image is quite nice, and the RGB does add a bit of 3-D to it compared to a normal narrowband Hubble palette like this one that I took last year: https://www.astrobin.com/full/g0bpv3/C/

What struck me about yours was the extraordinary amount of time you spent shooting this object compared to mine: i.e. 42 hours of data versus 10 hrs. And you had the advantage of a new high-falutin' CMOS camera that's some 3 times faster than my lowly QSI 683 with the slooow 8300 Kodak chip. Interestingly, we both had very close to the same 0.4 degree field radius. Your chip also has nearly 4 times the area of my QSI 683. The 10" F6.3 can cover a full frame format of course, I just didn't have the camera at the time to image with it.

Sooo, I'm using a 10" F6.3 flat field Mak-astrograph, and I have always been wondering if it's the right thing to spend time making in production, seeing as the SCTs of this size are so cheap. Maybe an SCT with an F6.3 reducer would negate the need for this scope?

Rolando

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 1:18 pm
Subject: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

I suggest that the AP1100AE be submitted to the FDA for approval as a sleep aide. 

I tend to wake up in the week hours when my system is imaging, and roll over and unlock the phone and RDP in to check how things are going.  Last couple of nights the PHD2 log, which pops up first, had the first digit of a 1. That is a definite incentive to just go back to sleep and let it keep doing what it is doing.  Better than Ambien.  Almost as good as Bourbon.  :) 

I'm in that period here in Florida where it rains too much but there are a few nights open with really still air, but the wind has not picked up as it does during the actual dry season. 

I did finally find enough nights in between rain to finish off the elephant trunk (here "finish" could be defined as "got tired of collecting data" moreso than "definitely got enough data" -- but let's not split hairs). 

This is at 2800mm in RGB + SHO (all rolled together).  It has 30s RGB stars, the color is more from broadband mixed with the narrow band, and all the detail is from 36 hours of narrow band data (vs only 5.9 of BB for color).  No luminance, just synthetic luminance from narrow band.  I went through a rainbow of color variations and settled here.

Criticism and suggestions welcomed.

Full size version: https://www.astrobin.com/85ed5q/0/

Linwood

PS. If you submit to the FDA, will Medicare then pay for the mounts? 


--
Roland Christen
Astro-Physics


Roland Christen
 


permanent collimation, a high quality focuser, etc
The main design parameters are fast focal ratio compared to an SCT, quartz mirror and carbon fiber tube for focus stability. I'm not sure if the latter two would be appreciated by imagers since people use focus routines to get around focus shift with temperature. The moment you add quartz optics and carbon fiber, you are adding several thousand to the retail price. Adding an Optec focuser adds another couple thou. So, is it worth it?

Rolando

-----Original Message-----
From: Bill Long <bill@...>
To: Roland Christen via groups.io <chris1011@...>; main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Fri, Sep 23, 2022 4:53 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

SCTs aren't bad, but have a number of issues that prevent me from wanting to use one for deep sky imaging. They are slow, the reducers for them aren't very good, focusing can cause mirror flopping/shifting issues, bright stars can get a reflection on them or elsewhere in images, they don't have good cooling out of the box, etc.

To get one really up to snuff for high quality imaging takes a lot of work and extra money. Even then you still have some issues you just cannot fix unless you design and engineer your own solutions, like Dr Hayes did.

As for the viability of the Mak Cass f6.3 I think the design improvements you mentioned with permanent collimation, a high quality focuser, etc would be hard to pass up. Ultimately that would depend on the price I guess.

Bill



From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Friday, September 23, 2022 12:08 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 
Some thoughts from the peanut gallery,

Although you may have clouds and rain, we here in the Midwest have both plus we are under the jet stream most of the time with lousy seeing. Last night as an example I was out testing scopes and software with seeing at an abysmal 3 arc sec FWHM with a scope that can produce 1.3 FWHM in good seeing.

So, having said that, your image is quite nice, and the RGB does add a bit of 3-D to it compared to a normal narrowband Hubble palette like this one that I took last year: https://www.astrobin.com/full/g0bpv3/C/

What struck me about yours was the extraordinary amount of time you spent shooting this object compared to mine: i.e. 42 hours of data versus 10 hrs. And you had the advantage of a new high-falutin' CMOS camera that's some 3 times faster than my lowly QSI 683 with the slooow 8300 Kodak chip. Interestingly, we both had very close to the same 0.4 degree field radius. Your chip also has nearly 4 times the area of my QSI 683. The 10" F6.3 can cover a full frame format of course, I just didn't have the camera at the time to image with it.

Sooo, I'm using a 10" F6.3 flat field Mak-astrograph, and I have always been wondering if it's the right thing to spend time making in production, seeing as the SCTs of this size are so cheap. Maybe an SCT with an F6.3 reducer would negate the need for this scope?

Rolando

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 1:18 pm
Subject: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

I suggest that the AP1100AE be submitted to the FDA for approval as a sleep aide. 

I tend to wake up in the week hours when my system is imaging, and roll over and unlock the phone and RDP in to check how things are going.  Last couple of nights the PHD2 log, which pops up first, had the first digit of a 1. That is a definite incentive to just go back to sleep and let it keep doing what it is doing.  Better than Ambien.  Almost as good as Bourbon.  :) 

I'm in that period here in Florida where it rains too much but there are a few nights open with really still air, but the wind has not picked up as it does during the actual dry season. 

I did finally find enough nights in between rain to finish off the elephant trunk (here "finish" could be defined as "got tired of collecting data" moreso than "definitely got enough data" -- but let's not split hairs). 

This is at 2800mm in RGB + SHO (all rolled together).  It has 30s RGB stars, the color is more from broadband mixed with the narrow band, and all the detail is from 36 hours of narrow band data (vs only 5.9 of BB for color).  No luminance, just synthetic luminance from narrow band.  I went through a rainbow of color variations and settled here.

Criticism and suggestions welcomed.

Full size version: https://www.astrobin.com/85ed5q/0/

Linwood

PS. If you submit to the FDA, will Medicare then pay for the mounts? 


--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


ap@CaptivePhotons.com
 

On Fri, Sep 23, 2022 at 03:09 PM, Roland Christen wrote:
What struck me about yours was the extraordinary amount of time you spent shooting this object compared to mine: i.e. 42 hours of data versus 10 hrs. And you had the advantage of a new high-falutin' CMOS camera that's some 3 times faster than my lowly QSI 683 with the slooow 8300 Kodak chip. Interestingly, we both had very close to the same 0.4 degree field radius. Your chip also has nearly 4 times the area of my QSI 683. The 10" F6.3 can cover a full frame format of course, I just didn't have the camera at the time to image with it.
 
Sooo, I'm using a 10" F6.3 flat field Mak-astrograph, and I have always been wondering if it's the right thing to spend time making in production, seeing as the SCTs of this size are so cheap. Maybe an SCT with an F6.3 reducer would negate the need for this scope?
A few thoughts... 

First, I still struggle with knowing when to stop imaging a target.  My current technique is run WBPP (PI) each morning to incorporate the latest, and see the integrated images.  When they stop getting better I stop.  Well, maybe... I also suffer from complications of moonlight (so I may still need RGB data and need to wait a bit), or maybe I lost disproportionately too much of one filter to clouds.  So I definitely tend to over-collect rather than under.  I was very surprised in this case that I got more contribution than I expected with very little RGB data. Though I think the longer narrow band, some drizzling, over-sampling and deconvolution brought out detail I would not have had with a lot less time.  And I think more data sometimes overcomes some of my lousy PI processing skills. 

I've used the 0.7x reducer from Celestron a few times, and am not excited. I still am unsure if I have a back focus issue, or if it just does not cover a full frame well.  Though I did get a decent pac-man with it (https://www.astrobin.com/full/32xnwf/0/), it's tough to get the corners to look decent.  Maybe I need to spend more time fine tuning it, but it is a pain to use with the lite crawler (more precisely a pain to change back and forth). 

I'm really curious to see how I feel about the C11 when I get some use of the 152 that's on order.  While 1200mm is not 2800mm, with the tiny pixels I figure I am seeing limited even in good time to somewhere in the 1500mm range.  And it will probably get rid of my super bloated stars.  But at present, especially in galaxy season and for clusters, I actually like the C11 quite a lot.

Thanks for the thoughts, your peanut gallery is still very exclusive territory, I appreciate your time.

Peter Nagy wrote: 

>>   
Almost as good as Bourbon.  :) 

 

>I prefer Scotch Whiskey. 😉 

Well, I understand how some like refractors, some reflectors; some mono, some OSC; some blonds, some redheads; some guided and some just let the scope wander... but Scotch?   (And I'm fairly sure my ancestors on my fathers side are from Scotland, so I realize its sacrilege). 

Linwood


Bill Long
 

Yeah, I sent the previous message from my mobile, so I kept it short. The quartz optics, and carbon tube would be great additions. I think it's worth it myself. There are not many 10" high quality scopes available for purchase. Especially not ones with a large, corrected field. 


From: chris1011@... <chris1011@...>
Sent: Friday, September 23, 2022 3:15 PM
To: bill@... <bill@...>; main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 

permanent collimation, a high quality focuser, etc
The main design parameters are fast focal ratio compared to an SCT, quartz mirror and carbon fiber tube for focus stability. I'm not sure if the latter two would be appreciated by imagers since people use focus routines to get around focus shift with temperature. The moment you add quartz optics and carbon fiber, you are adding several thousand to the retail price. Adding an Optec focuser adds another couple thou. So, is it worth it?

Rolando

-----Original Message-----
From: Bill Long <bill@...>
To: Roland Christen via groups.io <chris1011@...>; main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Fri, Sep 23, 2022 4:53 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

SCTs aren't bad, but have a number of issues that prevent me from wanting to use one for deep sky imaging. They are slow, the reducers for them aren't very good, focusing can cause mirror flopping/shifting issues, bright stars can get a reflection on them or elsewhere in images, they don't have good cooling out of the box, etc.

To get one really up to snuff for high quality imaging takes a lot of work and extra money. Even then you still have some issues you just cannot fix unless you design and engineer your own solutions, like Dr Hayes did.

As for the viability of the Mak Cass f6.3 I think the design improvements you mentioned with permanent collimation, a high quality focuser, etc would be hard to pass up. Ultimately that would depend on the price I guess.

Bill



From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Friday, September 23, 2022 12:08 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 
Some thoughts from the peanut gallery,

Although you may have clouds and rain, we here in the Midwest have both plus we are under the jet stream most of the time with lousy seeing. Last night as an example I was out testing scopes and software with seeing at an abysmal 3 arc sec FWHM with a scope that can produce 1.3 FWHM in good seeing.

So, having said that, your image is quite nice, and the RGB does add a bit of 3-D to it compared to a normal narrowband Hubble palette like this one that I took last year: https://www.astrobin.com/full/g0bpv3/C/

What struck me about yours was the extraordinary amount of time you spent shooting this object compared to mine: i.e. 42 hours of data versus 10 hrs. And you had the advantage of a new high-falutin' CMOS camera that's some 3 times faster than my lowly QSI 683 with the slooow 8300 Kodak chip. Interestingly, we both had very close to the same 0.4 degree field radius. Your chip also has nearly 4 times the area of my QSI 683. The 10" F6.3 can cover a full frame format of course, I just didn't have the camera at the time to image with it.

Sooo, I'm using a 10" F6.3 flat field Mak-astrograph, and I have always been wondering if it's the right thing to spend time making in production, seeing as the SCTs of this size are so cheap. Maybe an SCT with an F6.3 reducer would negate the need for this scope?

Rolando

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 1:18 pm
Subject: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

I suggest that the AP1100AE be submitted to the FDA for approval as a sleep aide. 

I tend to wake up in the week hours when my system is imaging, and roll over and unlock the phone and RDP in to check how things are going.  Last couple of nights the PHD2 log, which pops up first, had the first digit of a 1. That is a definite incentive to just go back to sleep and let it keep doing what it is doing.  Better than Ambien.  Almost as good as Bourbon.  :) 

I'm in that period here in Florida where it rains too much but there are a few nights open with really still air, but the wind has not picked up as it does during the actual dry season. 

I did finally find enough nights in between rain to finish off the elephant trunk (here "finish" could be defined as "got tired of collecting data" moreso than "definitely got enough data" -- but let's not split hairs). 

This is at 2800mm in RGB + SHO (all rolled together).  It has 30s RGB stars, the color is more from broadband mixed with the narrow band, and all the detail is from 36 hours of narrow band data (vs only 5.9 of BB for color).  No luminance, just synthetic luminance from narrow band.  I went through a rainbow of color variations and settled here.

Criticism and suggestions welcomed.

Full size version: https://www.astrobin.com/85ed5q/0/

Linwood

PS. If you submit to the FDA, will Medicare then pay for the mounts? 


--
Roland Christen
Astro-Physics


 

>>>SCTs aren't bad, but have a number of issues that prevent me from wanting to use one for deep sky imaging. They are slow, the reducers for them aren't very good, focusing can cause mirror flopping/shifting issues, bright stars can get a reflection on them or elsewhere in images, they don't have good cooling out of the box, etc.

Having just purchased a Celestron Edge HD 11" (for planetary) most of not all of these issues are solved in modern SCTs. That being said, it would probably not be my first choice, considering the comparatively inexpensive imaging newts or mak newts that do a comparable job. I have a 10" f4 newt and am quite happy with the results. The SCT would definitely take some work and (not inexpensive) reducer to get it in the usable realm for DSO

On Fri, Sep 23, 2022 at 2:53 PM Bill Long <bill@...> wrote:
SCTs aren't bad, but have a number of issues that prevent me from wanting to use one for deep sky imaging. They are slow, the reducers for them aren't very good, focusing can cause mirror flopping/shifting issues, bright stars can get a reflection on them or elsewhere in images, they don't have good cooling out of the box, etc.

To get one really up to snuff for high quality imaging takes a lot of work and extra money. Even then you still have some issues you just cannot fix unless you design and engineer your own solutions, like Dr Hayes did.

As for the viability of the Mak Cass f6.3 I think the design improvements you mentioned with permanent collimation, a high quality focuser, etc would be hard to pass up. Ultimately that would depend on the price I guess.

Bill



From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011=aol.com@groups.io>
Sent: Friday, September 23, 2022 12:08 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 
Some thoughts from the peanut gallery,

Although you may have clouds and rain, we here in the Midwest have both plus we are under the jet stream most of the time with lousy seeing. Last night as an example I was out testing scopes and software with seeing at an abysmal 3 arc sec FWHM with a scope that can produce 1.3 FWHM in good seeing.

So, having said that, your image is quite nice, and the RGB does add a bit of 3-D to it compared to a normal narrowband Hubble palette like this one that I took last year: https://www.astrobin.com/full/g0bpv3/C/

What struck me about yours was the extraordinary amount of time you spent shooting this object compared to mine: i.e. 42 hours of data versus 10 hrs. And you had the advantage of a new high-falutin' CMOS camera that's some 3 times faster than my lowly QSI 683 with the slooow 8300 Kodak chip. Interestingly, we both had very close to the same 0.4 degree field radius. Your chip also has nearly 4 times the area of my QSI 683. The 10" F6.3 can cover a full frame format of course, I just didn't have the camera at the time to image with it.

Sooo, I'm using a 10" F6.3 flat field Mak-astrograph, and I have always been wondering if it's the right thing to spend time making in production, seeing as the SCTs of this size are so cheap. Maybe an SCT with an F6.3 reducer would negate the need for this scope?

Rolando

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 1:18 pm
Subject: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

I suggest that the AP1100AE be submitted to the FDA for approval as a sleep aide. 

I tend to wake up in the week hours when my system is imaging, and roll over and unlock the phone and RDP in to check how things are going.  Last couple of nights the PHD2 log, which pops up first, had the first digit of a 1. That is a definite incentive to just go back to sleep and let it keep doing what it is doing.  Better than Ambien.  Almost as good as Bourbon.  :) 

I'm in that period here in Florida where it rains too much but there are a few nights open with really still air, but the wind has not picked up as it does during the actual dry season. 

I did finally find enough nights in between rain to finish off the elephant trunk (here "finish" could be defined as "got tired of collecting data" moreso than "definitely got enough data" -- but let's not split hairs). 

This is at 2800mm in RGB + SHO (all rolled together).  It has 30s RGB stars, the color is more from broadband mixed with the narrow band, and all the detail is from 36 hours of narrow band data (vs only 5.9 of BB for color).  No luminance, just synthetic luminance from narrow band.  I went through a rainbow of color variations and settled here.

Criticism and suggestions welcomed.

Full size version: https://www.astrobin.com/85ed5q/0/

Linwood

PS. If you submit to the FDA, will Medicare then pay for the mounts? 


--
Roland Christen
Astro-Physics




Ram
 

>>The main design parameters are fast focal ratio compared to an SCT, quartz mirror and carbon fiber tube for focus stability. I'm not sure if the latter two would be appreciated by imagers since people use focus routines to get around focus shift with temperature. The moment you add quartz optics and carbon fiber, you are adding several thousand to the retail price. Adding an Optec focuser adds another couple thou. So, is it worth it?

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus -- you will have aluminum in your image train anyway (camera, extension tubes etc.) So the goal of thermo-compensation might be better than the goal of zero expansion. 
You still need focusers and focus routines, IMHO. Unless I am missing something.


Emilio J. Robau, P.E.
 

A tool for every job.   Hard to beat a production C14 as a planitary imager.  I am thinking a C11 is in my future for that purpose given that one thing we enjoy way down here is excellent seeing.


Roland Christen
 


It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus
It may not, but it reduces the need for re-focusing from every 2 degrees F to around every 15 degrees F. In the summer i can leave the focus alone for pretty much all night. When a cold front moves thru we can sometimes get 30 degree temp shift in 3 hours time, which does require some focus touchup. In a Cassegrain, a slight shift of the corrector to mirror distance is amplified by the secondary amplification factor. In an SCT it is a factor of 5x. So aluminum tubes that shrink by 0.1mm from warm to cold will cause an image shift or 0.5mm. In my carbon fiber design there is no distance change and the amplification factor is only around 2.2x. The small amount of aluminum in the rear to the camera makes almost no difference. I've studied my design extensively in ATMOS and the shift is very small for a 15 degree F drop.

Roland


-----Original Message-----
From: Ram <ramviswanathan@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 6:37 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

>>The main design parameters are fast focal ratio compared to an SCT, quartz mirror and carbon fiber tube for focus stability. I'm not sure if the latter two would be appreciated by imagers since people use focus routines to get around focus shift with temperature. The moment you add quartz optics and carbon fiber, you are adding several thousand to the retail price. Adding an Optec focuser adds another couple thou. So, is it worth it?

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus -- you will have aluminum in your image train anyway (camera, extension tubes etc.) So the goal of thermo-compensation might be better than the goal of zero expansion. 
You still need focusers and focus routines, IMHO. Unless I am missing something.

--
Roland Christen
Astro-Physics


Bill Long
 

My AGO Optical 12.5" iDK uses Quartz optics and a truss system, and I rarely need to refocus it after the system has stabilized for the night. I have a 14" CDK that has yet to be unboxed and is sitting at my future observatory site, that also uses quartz optics, and I would imagine the experience will be the same.

The 10" Mak Cass f6.3 would definitely be welcomed, IMO. That is in the portable range for long focal length optics, which I would not call the 12.5 or 14" scopes portable by any means. Now, I don't know how much the scope weighs, but I would imagine it would not be too heavy. Maybe around 25 lbs? Combined with the permanently aligned optics, I would love to have that for a trip with the Mach 2 to a dark site.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Friday, September 23, 2022 5:10 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus
It may not, but it reduces the need for re-focusing from every 2 degrees F to around every 15 degrees F. In the summer i can leave the focus alone for pretty much all night. When a cold front moves thru we can sometimes get 30 degree temp shift in 3 hours time, which does require some focus touchup. In a Cassegrain, a slight shift of the corrector to mirror distance is amplified by the secondary amplification factor. In an SCT it is a factor of 5x. So aluminum tubes that shrink by 0.1mm from warm to cold will cause an image shift or 0.5mm. In my carbon fiber design there is no distance change and the amplification factor is only around 2.2x. The small amount of aluminum in the rear to the camera makes almost no difference. I've studied my design extensively in ATMOS and the shift is very small for a 15 degree F drop.

Roland


-----Original Message-----
From: Ram <ramviswanathan@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 6:37 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

>>The main design parameters are fast focal ratio compared to an SCT, quartz mirror and carbon fiber tube for focus stability. I'm not sure if the latter two would be appreciated by imagers since people use focus routines to get around focus shift with temperature. The moment you add quartz optics and carbon fiber, you are adding several thousand to the retail price. Adding an Optec focuser adds another couple thou. So, is it worth it?

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus -- you will have aluminum in your image train anyway (camera, extension tubes etc.) So the goal of thermo-compensation might be better than the goal of zero expansion. 
You still need focusers and focus routines, IMHO. Unless I am missing something.

--
Roland Christen
Astro-Physics


Bill Long
 

I forgot to ask, does this Mak Cass have cooling fans on the rear blowing outward?

From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Bill Long <bill@...>
Sent: Friday, September 23, 2022 5:47 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 
My AGO Optical 12.5" iDK uses Quartz optics and a truss system, and I rarely need to refocus it after the system has stabilized for the night. I have a 14" CDK that has yet to be unboxed and is sitting at my future observatory site, that also uses quartz optics, and I would imagine the experience will be the same.

The 10" Mak Cass f6.3 would definitely be welcomed, IMO. That is in the portable range for long focal length optics, which I would not call the 12.5 or 14" scopes portable by any means. Now, I don't know how much the scope weighs, but I would imagine it would not be too heavy. Maybe around 25 lbs? Combined with the permanently aligned optics, I would love to have that for a trip with the Mach 2 to a dark site.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Friday, September 23, 2022 5:10 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus
It may not, but it reduces the need for re-focusing from every 2 degrees F to around every 15 degrees F. In the summer i can leave the focus alone for pretty much all night. When a cold front moves thru we can sometimes get 30 degree temp shift in 3 hours time, which does require some focus touchup. In a Cassegrain, a slight shift of the corrector to mirror distance is amplified by the secondary amplification factor. In an SCT it is a factor of 5x. So aluminum tubes that shrink by 0.1mm from warm to cold will cause an image shift or 0.5mm. In my carbon fiber design there is no distance change and the amplification factor is only around 2.2x. The small amount of aluminum in the rear to the camera makes almost no difference. I've studied my design extensively in ATMOS and the shift is very small for a 15 degree F drop.

Roland


-----Original Message-----
From: Ram <ramviswanathan@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 6:37 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

>>The main design parameters are fast focal ratio compared to an SCT, quartz mirror and carbon fiber tube for focus stability. I'm not sure if the latter two would be appreciated by imagers since people use focus routines to get around focus shift with temperature. The moment you add quartz optics and carbon fiber, you are adding several thousand to the retail price. Adding an Optec focuser adds another couple thou. So, is it worth it?

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus -- you will have aluminum in your image train anyway (camera, extension tubes etc.) So the goal of thermo-compensation might be better than the goal of zero expansion. 
You still need focusers and focus routines, IMHO. Unless I am missing something.

--
Roland Christen
Astro-Physics


Ram
 

Is it possible to design a system that is perfectly thermo-compensated (within a 15F temp swing)? 

I have one of Yuri's scopes (TEC ADL300) that uses a combination of titanium truss tubes and aluminum spider that extends out in front of the truss.  So when the temperature drops, the titanium shrinks but the aluminum shrinks even more. 
That is compensated by the shrinkage of the aluminum extension tubes in the back in the opposite direction. I thought that design was quite clever. 

This way you focus once in the beginning of the night and you're done!


Roland Christen
 

No cooling fans - they are not needed. The mirror is light weight and fairly thin, so it cools down quickly. The back can be fully opened during cool-down. I have not seen any thermal issues.

Roland


-----Original Message-----
From: Bill Long <bill@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Fri, Sep 23, 2022 8:04 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

I forgot to ask, does this Mak Cass have cooling fans on the rear blowing outward?

From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Bill Long <bill@...>
Sent: Friday, September 23, 2022 5:47 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 
My AGO Optical 12.5" iDK uses Quartz optics and a truss system, and I rarely need to refocus it after the system has stabilized for the night. I have a 14" CDK that has yet to be unboxed and is sitting at my future observatory site, that also uses quartz optics, and I would imagine the experience will be the same.

The 10" Mak Cass f6.3 would definitely be welcomed, IMO. That is in the portable range for long focal length optics, which I would not call the 12.5 or 14" scopes portable by any means. Now, I don't know how much the scope weighs, but I would imagine it would not be too heavy. Maybe around 25 lbs? Combined with the permanently aligned optics, I would love to have that for a trip with the Mach 2 to a dark site.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Friday, September 23, 2022 5:10 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus
It may not, but it reduces the need for re-focusing from every 2 degrees F to around every 15 degrees F. In the summer i can leave the focus alone for pretty much all night. When a cold front moves thru we can sometimes get 30 degree temp shift in 3 hours time, which does require some focus touchup. In a Cassegrain, a slight shift of the corrector to mirror distance is amplified by the secondary amplification factor. In an SCT it is a factor of 5x. So aluminum tubes that shrink by 0.1mm from warm to cold will cause an image shift or 0.5mm. In my carbon fiber design there is no distance change and the amplification factor is only around 2.2x. The small amount of aluminum in the rear to the camera makes almost no difference. I've studied my design extensively in ATMOS and the shift is very small for a 15 degree F drop.

Roland


-----Original Message-----
From: Ram <ramviswanathan@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 6:37 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

>>The main design parameters are fast focal ratio compared to an SCT, quartz mirror and carbon fiber tube for focus stability. I'm not sure if the latter two would be appreciated by imagers since people use focus routines to get around focus shift with temperature. The moment you add quartz optics and carbon fiber, you are adding several thousand to the retail price. Adding an Optec focuser adds another couple thou. So, is it worth it?

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus -- you will have aluminum in your image train anyway (camera, extension tubes etc.) So the goal of thermo-compensation might be better than the goal of zero expansion. 
You still need focusers and focus routines, IMHO. Unless I am missing something.

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


Roland Christen
 

The main thermal effects of the 10" Mak are not so much focus shift but getting the optics to shed heat to eliminate tube currents. My design is a closed tube and consists of a front corrector lens, a secondary mirror assembly and a primary mirror in the rear. The front corrector sheds heat very fast because it is aimed at the dark sky so it radiates heat into the dark void. The mirror is insulated from that because it has an aluminum coating, so it cannot radiate heat the same way. Therefore we make the mirror quite thin and lightweight, plus the rear has removable louvers to allow the mirror's heat to escape. The main baffle is also designed to prevent warm air from rising inside the tube, so that prevents heat plumes from forming during cooldown.

An open tube truss design has some advantages when it comes to controlling tube currents, but there are a number of disadvantages too. Your mirror coatings are exposed to the air and can get atmospheric schmutz buildup. My 17" open tube truss has a very dirty mirror after a few years of operation in my observatory. Loss of contrast is the main result. I hate to clean it because aluminum coatings are somewhat fragile and cleaning can cause micro-scratches and sleeks. In a closed tube design the mirrors will stay pristine and only the front surface of the corrector needs to be cleaned - and those coatings are very robust and will not scratch with careful cleaning.

Roland

-----Original Message-----
From: Ram <ramviswanathan@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 8:08 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

Is it possible to design a system that is perfectly thermo-compensated (within a 15F temp swing)? 

I have one of Yuri's scopes (TEC ADL300) that uses a combination of titanium truss tubes and aluminum spider that extends out in front of the truss.  So when the temperature drops, the titanium shrinks but the aluminum shrinks even more. 
That is compensated by the shrinkage of the aluminum extension tubes in the back in the opposite direction. I thought that design was quite clever. 

This way you focus once in the beginning of the night and you're done!


--
Roland Christen
Astro-Physics


Ram
 

Makes complete sense. Thanks.


Bill Long
 


Awesome! Sounds great.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Saturday, September 24, 2022 8:32 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 
No cooling fans - they are not needed. The mirror is light weight and fairly thin, so it cools down quickly. The back can be fully opened during cool-down. I have not seen any thermal issues.

Roland


-----Original Message-----
From: Bill Long <bill@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Fri, Sep 23, 2022 8:04 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

I forgot to ask, does this Mak Cass have cooling fans on the rear blowing outward?

From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Bill Long <bill@...>
Sent: Friday, September 23, 2022 5:47 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 
My AGO Optical 12.5" iDK uses Quartz optics and a truss system, and I rarely need to refocus it after the system has stabilized for the night. I have a 14" CDK that has yet to be unboxed and is sitting at my future observatory site, that also uses quartz optics, and I would imagine the experience will be the same.

The 10" Mak Cass f6.3 would definitely be welcomed, IMO. That is in the portable range for long focal length optics, which I would not call the 12.5 or 14" scopes portable by any means. Now, I don't know how much the scope weighs, but I would imagine it would not be too heavy. Maybe around 25 lbs? Combined with the permanently aligned optics, I would love to have that for a trip with the Mach 2 to a dark site.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Friday, September 23, 2022 5:10 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus
It may not, but it reduces the need for re-focusing from every 2 degrees F to around every 15 degrees F. In the summer i can leave the focus alone for pretty much all night. When a cold front moves thru we can sometimes get 30 degree temp shift in 3 hours time, which does require some focus touchup. In a Cassegrain, a slight shift of the corrector to mirror distance is amplified by the secondary amplification factor. In an SCT it is a factor of 5x. So aluminum tubes that shrink by 0.1mm from warm to cold will cause an image shift or 0.5mm. In my carbon fiber design there is no distance change and the amplification factor is only around 2.2x. The small amount of aluminum in the rear to the camera makes almost no difference. I've studied my design extensively in ATMOS and the shift is very small for a 15 degree F drop.

Roland


-----Original Message-----
From: Ram <ramviswanathan@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 6:37 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

>>The main design parameters are fast focal ratio compared to an SCT, quartz mirror and carbon fiber tube for focus stability. I'm not sure if the latter two would be appreciated by imagers since people use focus routines to get around focus shift with temperature. The moment you add quartz optics and carbon fiber, you are adding several thousand to the retail price. Adding an Optec focuser adds another couple thou. So, is it worth it?

It doesnt appear that quartz optics and carbon fiber actually eliminate the need for autofocus -- you will have aluminum in your image train anyway (camera, extension tubes etc.) So the goal of thermo-compensation might be better than the goal of zero expansion. 
You still need focusers and focus routines, IMHO. Unless I am missing something.

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


Bill Long
 

This is a well thought out design. Maybe someday we'll get the chance to buy one. 😊



From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Saturday, September 24, 2022 8:48 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide
 
The main thermal effects of the 10" Mak are not so much focus shift but getting the optics to shed heat to eliminate tube currents. My design is a closed tube and consists of a front corrector lens, a secondary mirror assembly and a primary mirror in the rear. The front corrector sheds heat very fast because it is aimed at the dark sky so it radiates heat into the dark void. The mirror is insulated from that because it has an aluminum coating, so it cannot radiate heat the same way. Therefore we make the mirror quite thin and lightweight, plus the rear has removable louvers to allow the mirror's heat to escape. The main baffle is also designed to prevent warm air from rising inside the tube, so that prevents heat plumes from forming during cooldown.

An open tube truss design has some advantages when it comes to controlling tube currents, but there are a number of disadvantages too. Your mirror coatings are exposed to the air and can get atmospheric schmutz buildup. My 17" open tube truss has a very dirty mirror after a few years of operation in my observatory. Loss of contrast is the main result. I hate to clean it because aluminum coatings are somewhat fragile and cleaning can cause micro-scratches and sleeks. In a closed tube design the mirrors will stay pristine and only the front surface of the corrector needs to be cleaned - and those coatings are very robust and will not scratch with careful cleaning.

Roland

-----Original Message-----
From: Ram <ramviswanathan@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 23, 2022 8:08 pm
Subject: Re: [ap-gto] Elephant Trunk, AP1100AE as a sleep aide

Is it possible to design a system that is perfectly thermo-compensated (within a 15F temp swing)? 

I have one of Yuri's scopes (TEC ADL300) that uses a combination of titanium truss tubes and aluminum spider that extends out in front of the truss.  So when the temperature drops, the titanium shrinks but the aluminum shrinks even more. 
That is compensated by the shrinkage of the aluminum extension tubes in the back in the opposite direction. I thought that design was quite clever. 

This way you focus once in the beginning of the night and you're done!


--
Roland Christen
Astro-Physics