Date   

Re: End of an era?

Roland Christen
 

First, there are tons of SCTs coming from China now that it is impractical to make a hand figured folded optic. People call them superb although tests show consistently that they are barely 1/4 wave. I have never seen a truly superb one. However, even at just 1/4 wave, they are capable of making truly great digital images using "Lucky Imaging" techniques, with video cameras, where resolution is high and contrast can be boosted to show fleeting detail. You can get a 14" scope for the price of a hand figured 6" Mak.

The Maksutov Cassegrain optical system has an inherent 5th order spherical defect that requires hand correction. They can be made cheaply if you allow all surfaces to be spherical and have a largish central obstruction and allow 1/3 to 1/4 wave of spherical error. The smaller the obstruction is, the worse the 5th order becomes. Doing hand correcting on the 10" mirror of our Maks takes 5 to 15 hours of careful hand work. Figuring cycle can be as little as 15 seconds at a time, followed by 10 - 15 minutes of testing on the interferometer. There are very few people who have the patience and knowledge to do this task.

Getting the correction down to the level of 1/10 wave P-V is not trivial, but results in superb contrast visually. The eyeball cannot artificially turn up the contrast, and if the optic is corrected to only 1/3 - 1/4 wave, the contrast drops in half. Add to that a large central obstruction and the contrast drops even more.

The requirement for a superb visual instrument is different than for an imaging instrument. Superb visual scopes require a higher level of correction. Most of that knowledge is lost now that electronic imaging is so advanced. The cost in time, knowledge and treasure is high.

Rolando



-----Original Message-----
From: Terri Zittritsch <theresamarie11@...>
To: main@ap-ug.groups.io
Sent: Sat, Aug 1, 2020 7:54 am
Subject: Re: [ap-ug] End of an era?

Roland, in reading your post, it seemed like you have concluded that production of these beautiful scopes is no longer warranted due to the accessibility of imaging.    When I first decided to invest in some astro Physics equipment, the first thing you notice is that almost nothing is available to buy, and/or even available for backorder (getting on a list).     Did you see a real drop in people wanting to get on the list for the 10", and therefore some time ago stopped accepting new back orders?    

I know that while I love refractors for their pinpoint stars, my next favorite scopes are the folded light class... you get such a huge bang for the buck in a portable package!    At outreach events here in Vermont, I frequently hear that I have the best views through my little 8" Meade ACF, and while the general public may not know all of what to look for, I find the images pleasing as well.   I guess if I want one of your beauties, I'll have to watch on the second hand market now.

Terri


Re: End of an era?

Roland Christen
 

That is one made by Telescope Engineering Company.

Rolando



-----Original Message-----
From: Jay Freeman via groups.io <Jay_Reynolds_Freeman@...>
To: main@ap-ug.groups.io
Sent: Fri, Jul 31, 2020 5:59 pm
Subject: Re: [ap-ug] End of an era?

Roland wrote ...

It used to be that there was much more visual astronomy than there is today, probably because imaging was hard in the film days and for the first couple of years when we had small chips to do electronic imaging. Nowadays it is impossible to get visual views that remotely resemble what you can do with a few thousand bucks worth of electronic equipment. 

All true about the quality of electronically obtained images, but there is another side to the coin: I have had a fairly high-tech career -- PhD in physics, tail end of the Apollo program, a couple of artificial intelligence labs, Sun Microsystems Lab, and SpaceX -- even a little image processing, for that matter. Rather early on, I made a conscience decision to keep my hobbies low-tech, for diversity and for better relaxation. Thus I have deliberately avoided anything resembling imaging -- my astronomy, at least as an amateur, has always been strictly visual. Surely there are others who think the way I do?

Now that I have retired, I have added a little technology into the mix: Besides visual astronomy, cats, roses and guitar playing, I have been building a few guitar amplifiers. But the vacuum-tube stuff involved is so old that it is basically steampunk, so I'm not sure it counts ...

BTW, Roland, what are you using for an eyepiece turret on that AP-10?

-- Jay Reynolds Freeman
---------------------
Jay_Reynolds_Freeman@...
http://JayReynoldsFreeman.com
(personal web site)


Re: End of an era?

Terri Zittritsch
 

Roland, in reading your post, it seemed like you have concluded that production of these beautiful scopes is no longer warranted due to the accessibility of imaging.    When I first decided to invest in some astro Physics equipment, the first thing you notice is that almost nothing is available to buy, and/or even available for backorder (getting on a list).     Did you see a real drop in people wanting to get on the list for the 10", and therefore some time ago stopped accepting new back orders?    

I know that while I love refractors for their pinpoint stars, my next favorite scopes are the folded light class... you get such a huge bang for the buck in a portable package!    At outreach events here in Vermont, I frequently hear that I have the best views through my little 8" Meade ACF, and while the general public may not know all of what to look for, I find the images pleasing as well.   I guess if I want one of your beauties, I'll have to watch on the second hand market now.

Terri


Re: More dark nebulae with the Stowaway........

Steve Armen
 

Nicely done!


On Mon, Jul 27, 2020 at 7:49 AM Steve Nightingale <slnightingale@...> wrote:
Took another shot of IC5146 (The Cocoon) with Barnard 168. Nikon 5300DSLR, 4h 30m worth of stacked 2 minute subs. Skies muggy and a bit hazy.

The Stowaway gives a nice image scale to frame the combination well.

I may not have nailed the focus as well as I could have; image is uncropped so you can see coverage with the APS-C sensor.

https://ap-ug.groups.io/g/main/photo/249705/0?p=Created,,,20,2,0,0

Steve


Re: End of an era?

Jay Freeman
 

Roland wrote ...

It used to be that there was much more visual astronomy than there is today, probably because imaging was hard in the film days and for the first couple of years when we had small chips to do electronic imaging. Nowadays it is impossible to get visual views that remotely resemble what you can do with a few thousand bucks worth of electronic equipment. 

All true about the quality of electronically obtained images, but there is another side to the coin: I have had a fairly high-tech career -- PhD in physics, tail end of the Apollo program, a couple of artificial intelligence labs, Sun Microsystems Lab, and SpaceX -- even a little image processing, for that matter. Rather early on, I made a conscience decision to keep my hobbies low-tech, for diversity and for better relaxation. Thus I have deliberately avoided anything resembling imaging -- my astronomy, at least as an amateur, has always been strictly visual. Surely there are others who think the way I do?

Now that I have retired, I have added a little technology into the mix: Besides visual astronomy, cats, roses and guitar playing, I have been building a few guitar amplifiers. But the vacuum-tube stuff involved is so old that it is basically steampunk, so I'm not sure it counts ...

BTW, Roland, what are you using for an eyepiece turret on that AP-10?

-- Jay Reynolds Freeman
---------------------
Jay_Reynolds_Freeman@...
http://JayReynoldsFreeman.com
(personal web site)


Re: End of an era?

Alan
 

Roland,

The Mak and the little Stowaway, what a sweet combination!

Clear skies, Alan

On 7/31/2020 6:16 PM, Roland Christen via groups.io wrote:
Hi Astronuts,

Today I finished the last of the 10" F14.5 Maks, which will go to whoever is on our list. This is the last of my hand figured Maks that I plan to make of this size and focal length in production. It used to be that there was much more visual astronomy than there is today, probably because imaging was hard in the film days and for the first couple of years when we had small chips to do electronic imaging. Nowadays it is impossible to get visual views that remotely resemble what you can do with a few thousand bucks worth of electronic equipment.

That said, here is my last production Mak, aimed at a far distant telephone pole insulator which has a glint of sunshine that shows up as an artificial star. With a 5mm SPL ocular (737x) I see a tight high contrast Airy disc at focus. For those who don't know what that is - an Airy disc is the smallest resolvable spot from a distant point source that can be seen in any telescope. For a 10" it's approximately 4.5 arc seconds, and is surrounded by a few faint diffraction rings. With a scope like this I once saw the Sirius Pup in the Florida Keys when the separation was a mere 4 arc seconds.

Business end of the mighty Mak


Let there be light and minimal obstruction


The little Stowaway couldn't help hitching a ride on it's big sister


Re: More dark nebulae with the Stowaway........

Steve Nightingale
 

Hi Rick,

I had it H-alpha modified by LifePixel. No cooling. I do as many light frames as possible (usually 3-4 hours worth) and take bias, dark, and flat calibration frames. Stacking in DSS and some fussing in Photoshop.

I'm totally happy with the set-up. Uncomplicated and fun, with very satisfying results!

Look over my other photos to see what else I've done with the D5300.

Steve


Re: End of an era?

Alan Friedman
 

Bravo Rolando and congratulations on this milestone. This scope will join its sisters and continue to dazzle stargazers around the world for years to come.

Alan




On Jul 31, 2020, at 3:16 PM, Roland Christen via groups.io <chris1011@...> wrote:


Hi Astronuts,

Today I finished the last of the 10" F14.5 Maks, which will go to whoever is on our list. This is the last of my hand figured Maks that I plan to make of this size and focal length in production. It used to be that there was much more visual astronomy than there is today, probably because imaging was hard in the film days and for the first couple of years when we had small chips to do electronic imaging. Nowadays it is impossible to get visual views that remotely resemble what you can do with a few thousand bucks worth of electronic equipment.

That said, here is my last production Mak, aimed at a far distant telephone pole insulator which has a glint of sunshine that shows up as an artificial star. With a 5mm SPL ocular (737x) I see a tight high contrast Airy disc at focus. For those who don't know what that is - an Airy disc is the smallest resolvable spot from a distant point source that can be seen in any telescope. For a 10" it's approximately 4.5 arc seconds, and is surrounded by a few faint diffraction rings. With a scope like this I once saw the Sirius Pup in the Florida Keys when the separation was a mere 4 arc seconds.

<dummyfile.0.part>
Business end of the mighty Mak


<dummyfile.1.part>
Let there be light and minimal obstruction


<dummyfile.2.part>
The little Stowaway couldn't help hitching a ride on it's big sister


Re: [ap-gto] [ap-ug] End of an era?

thefamily90 Phillips
 

Well, I have imaged the Moon and Planets with mine (earlier version) and could not be happier with its performance. I may be part of the end of the era of visual observations and am happy to say I have spent hours and hours at the eyepiece of telescopes. I can certainly image more detail on Jupiter with my 10” than I can see but the longer I look the more I can see. And, in my opinion, very few images match the aesthetic beauty of Jupiter through the eyepiece of my telescope!

Jim Phillips 

Image.jpeg<main@ap-gto.groups.io> on behalf of Pete Lardizabal <p14@...>

Sent: Friday, July 31, 2020 6:32 PM
To: main@ap-ug.groups.io
Cc: main@ap-gto.groups.io
Subject: Re: [ap-gto] [ap-ug] End of an era?
 
WOW! Simply beautiful!

More rare than hens teeth...

😎

Pete

On Jul 31, 2020, at 6:17 PM, Roland Christen via groups.io <chris1011@...> wrote:


Hi Astronuts,

Today I finished the last of the 10" F14.5 Maks, which will go to whoever is on our list. This is the last of my hand figured Maks that I plan to make of this size and focal length in production. It used to be that there was much more visual astronomy than there is today, probably because imaging was hard in the film days and for the first couple of years when we had small chips to do electronic imaging. Nowadays it is impossible to get visual views that remotely resemble what you can do with a few thousand bucks worth of electronic equipment.

That said, here is my last production Mak, aimed at a far distant telephone pole insulator which has a glint of sunshine that shows up as an artificial star. With a 5mm SPL ocular (737x) I see a tight high contrast Airy disc at focus. For those who don't know what that is - an Airy disc is the smallest resolvable spot from a distant point source that can be seen in any telescope. For a 10" it's approximately 4.5 arc seconds, and is surrounded by a few faint diffraction rings. With a scope like this I once saw the Sirius Pup in the Florida Keys when the separation was a mere 4 arc seconds.

<dummyfile.0.part>
Business end of the mighty Mak


<dummyfile.1.part>
Let there be light and minimal obstruction


<dummyfile.2.part>
The little Stowaway couldn't help hitching a ride on it's big sister

--
Jim Phillips


Re: End of an era?

Stewart Valentine
 

Wish that was me. Alas it is not...............

On Fri, Jul 31, 2020 at 4:32 PM Pete Lardizabal <p14@...> wrote:
WOW! Simply beautiful!

More rare than hens teeth...

😎

Pete

On Jul 31, 2020, at 6:17 PM, Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:


Hi Astronuts,

Today I finished the last of the 10" F14.5 Maks, which will go to whoever is on our list. This is the last of my hand figured Maks that I plan to make of this size and focal length in production. It used to be that there was much more visual astronomy than there is today, probably because imaging was hard in the film days and for the first couple of years when we had small chips to do electronic imaging. Nowadays it is impossible to get visual views that remotely resemble what you can do with a few thousand bucks worth of electronic equipment.

That said, here is my last production Mak, aimed at a far distant telephone pole insulator which has a glint of sunshine that shows up as an artificial star. With a 5mm SPL ocular (737x) I see a tight high contrast Airy disc at focus. For those who don't know what that is - an Airy disc is the smallest resolvable spot from a distant point source that can be seen in any telescope. For a 10" it's approximately 4.5 arc seconds, and is surrounded by a few faint diffraction rings. With a scope like this I once saw the Sirius Pup in the Florida Keys when the separation was a mere 4 arc seconds.

<dummyfile.0.part>
Business end of the mighty Mak


<dummyfile.1.part>
Let there be light and minimal obstruction


<dummyfile.2.part>
The little Stowaway couldn't help hitching a ride on it's big sister


Re: End of an era?

Pete Lardizabal
 

WOW! Simply beautiful!

More rare than hens teeth...

😎

Pete

On Jul 31, 2020, at 6:17 PM, Roland Christen via groups.io <chris1011@...> wrote:


Hi Astronuts,

Today I finished the last of the 10" F14.5 Maks, which will go to whoever is on our list. This is the last of my hand figured Maks that I plan to make of this size and focal length in production. It used to be that there was much more visual astronomy than there is today, probably because imaging was hard in the film days and for the first couple of years when we had small chips to do electronic imaging. Nowadays it is impossible to get visual views that remotely resemble what you can do with a few thousand bucks worth of electronic equipment.

That said, here is my last production Mak, aimed at a far distant telephone pole insulator which has a glint of sunshine that shows up as an artificial star. With a 5mm SPL ocular (737x) I see a tight high contrast Airy disc at focus. For those who don't know what that is - an Airy disc is the smallest resolvable spot from a distant point source that can be seen in any telescope. For a 10" it's approximately 4.5 arc seconds, and is surrounded by a few faint diffraction rings. With a scope like this I once saw the Sirius Pup in the Florida Keys when the separation was a mere 4 arc seconds.

<dummyfile.0.part>
Business end of the mighty Mak


<dummyfile.1.part>
Let there be light and minimal obstruction


<dummyfile.2.part>
The little Stowaway couldn't help hitching a ride on it's big sister


End of an era?

Roland Christen
 

Hi Astronuts,

Today I finished the last of the 10" F14.5 Maks, which will go to whoever is on our list. This is the last of my hand figured Maks that I plan to make of this size and focal length in production. It used to be that there was much more visual astronomy than there is today, probably because imaging was hard in the film days and for the first couple of years when we had small chips to do electronic imaging. Nowadays it is impossible to get visual views that remotely resemble what you can do with a few thousand bucks worth of electronic equipment.

That said, here is my last production Mak, aimed at a far distant telephone pole insulator which has a glint of sunshine that shows up as an artificial star. With a 5mm SPL ocular (737x) I see a tight high contrast Airy disc at focus. For those who don't know what that is - an Airy disc is the smallest resolvable spot from a distant point source that can be seen in any telescope. For a 10" it's approximately 4.5 arc seconds, and is surrounded by a few faint diffraction rings. With a scope like this I once saw the Sirius Pup in the Florida Keys when the separation was a mere 4 arc seconds.

Business end of the mighty Mak


Let there be light and minimal obstruction


The little Stowaway couldn't help hitching a ride on it's big sister


Re: M23 & B84 w/92

Chris Cook
 

Thanks Stuart!
Chris
 

 

----- Original Message -----
From: Stuart <stuart.j.heggie@...>
Reply-To: <main@ap-ug.groups.io>
To: <main@ap-ug.groups.io>
Sent: 7/31/2020 10:08:31 AM
Subject: Re: [ap-ug] M23 & B84 w/92

Wonderful shot Chris!


On Fri, 31 Jul 2020 at 09:05, Chris Cook <chris@...> wrote:
Here's a region of the summer Milky Way often overlooked being just north of the more well known objects, the Lagoon & Trifid Nebulae.  B84 is the dark nebula region at upper left while the open cluster M23 is at lower right. 92mm Stowaway and Canon 6D.
 
 
Chris


Re: First try at GIF of comet rotation

Chris Cook
 

Excellent job!
 
Chris


 

----- Original Message -----
From: Roland Christen via groups.io <chris1011@...>
Reply-To: <main@ap-ug.groups.io>
To: <main@ap-gto.groups.io>, <main@ap-ug.groups.io>
Sent: 7/30/2020 2:49:33 PM
Subject: [ap-ug] First try at GIF of comet rotation

https://www.astrobin.com/full/nak28s/B/

Rolando


Re: First try at GIF of comet rotation

Julio Bird
 

Beautiful. Thanks for sharing it!


On Jul 30, 2020, at 3:49 PM, David Albers <humealbers@...> wrote:



Fantastic!


Re: More dark nebulae with the Stowaway........

Rick Socarras
 

Fantastic images!

The Nikon 5300 is modified with a full spectrum filter or Ha?  Does it have any cooling?  It's an amazing performer and I won't hide the fact that I own one and I'm seriously thinking of modifying it based on your incredible images! 

Rick 


Re: M23 & B84 w/92

Chris Cook
 

Thanks Pete!
This summer is for going after dark nebula.  I'm hoping August's weather is better up here, July was pretty hazy and humid.
 
Chris
 


 

----- Original Message -----
From: Pete Lardizabal <p14@...>
Reply-To: <main@ap-ug.groups.io>
To: <main@ap-ug.groups.io>
Sent: 7/31/2020 9:53:50 AM
Subject: Re: [ap-ug] M23 & B84 w/92

Great field Chris!

Great to see you keeping that Stowaway busy. 

😎

Pete

On Jul 31, 2020, at 9:13 AM, Chris Cook <chris@...> wrote:

 Here's a region of the summer Milky Way often overlooked being just north of the more well known objects, the Lagoon & Trifid Nebulae.  B84 is the dark nebula region at upper left while the open cluster M23 is at lower right. 92mm Stowaway and Canon 6D.
 
 
Chris


Re: M23 & B84 w/92

Stuart
 

Wonderful shot Chris!


On Fri, 31 Jul 2020 at 09:05, Chris Cook <chris@...> wrote:
Here's a region of the summer Milky Way often overlooked being just north of the more well known objects, the Lagoon & Trifid Nebulae.  B84 is the dark nebula region at upper left while the open cluster M23 is at lower right. 92mm Stowaway and Canon 6D.
 
 
Chris


Re: M23 & B84 w/92

Pete Lardizabal
 

Great field Chris!

Great to see you keeping that Stowaway busy. 

😎

Pete

On Jul 31, 2020, at 9:13 AM, Chris Cook <chris@...> wrote:

 Here's a region of the summer Milky Way often overlooked being just north of the more well known objects, the Lagoon & Trifid Nebulae.  B84 is the dark nebula region at upper left while the open cluster M23 is at lower right. 92mm Stowaway and Canon 6D.
 
 
Chris


M23 & B84 w/92

Chris Cook
 

Here's a region of the summer Milky Way often overlooked being just north of the more well known objects, the Lagoon & Trifid Nebulae.  B84 is the dark nebula region at upper left while the open cluster M23 is at lower right. 92mm Stowaway and Canon 6D.
 
 
Chris