Interesting way to image with a cheap mount


Roland Christen
 

I recently saw an image taken with a cheap mount that shows nice tight round stars, even though the mount might have a fair amount of tracking error that bloats the stars and makes them oval during long exposures. How is that possible, you ask?

The idea is to take the images, stack them and remove the stars with software now available. Then take a series of very short RGB exposures, stack them, extract the stars and paste them on the previous long exposures. Presto - you have a premium image with nice tight round stars. And people will point to your image and proclaim that you don't need fancy equipment to get perfect results. Of course the background image is not sharp, but who looks at that when the stars are tiny and round! Nice trick, no?

Rolando

--
Roland Christen
Astro-Physics


Jeff B
 

Actually clever.  Maybe they should run for public office too.


On Thu, Sep 9, 2021 at 3:52 PM Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:
I recently saw an image taken with a cheap mount that shows nice tight round stars, even though the mount might have a fair amount of tracking error that bloats the stars and makes them oval during long exposures. How is that possible, you ask?

The idea is to take the images, stack them and remove the stars with software now available. Then take a series of very short RGB exposures, stack them, extract the stars and paste them on the previous long exposures. Presto - you have a premium image with nice tight round stars. And people will point to your image and proclaim that you don't need fancy equipment to get perfect results. Of course the background image is not sharp, but who looks at that when the stars are tiny and round! Nice trick, no?

Rolando

--
Roland Christen
Astro-Physics


Bill Long
 

Yeah that's definitely a thing. I'm of course opposed to such things, but I also am the type that will spend hours working to squeeze every tiny bit of performance from optics and gets OCD about stars in images. To me it's all a part of the learning journey in the hobby. But for some the shortcuts are very compelling.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Thursday, September 9, 2021 12:52 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: [ap-gto] Interesting way to image with a cheap mount
 
I recently saw an image taken with a cheap mount that shows nice tight round stars, even though the mount might have a fair amount of tracking error that bloats the stars and makes them oval during long exposures. How is that possible, you ask?

The idea is to take the images, stack them and remove the stars with software now available. Then take a series of very short RGB exposures, stack them, extract the stars and paste them on the previous long exposures. Presto - you have a premium image with nice tight round stars. And people will point to your image and proclaim that you don't need fancy equipment to get perfect results. Of course the background image is not sharp, but who looks at that when the stars are tiny and round! Nice trick, no?

Rolando

--
Roland Christen
Astro-Physics


Dean Jacobsen
 

On Thu, Sep 9, 2021 at 12:52 PM, Roland Christen wrote:
Nice trick, no?
No.
 
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Christopher M
 


Christopher M
 

While I jest with the image of Marvin the Martian, it does bring up an interesting point:  Are not all of our processed images technically a blend of Art and Science?  Every time w Enhance Colour, Increase Contrast, Image Burn or Image Mask, False Colour assemble, etc etc, we are taking artistic liberties with the source.  True we are trying to bring out subtle details in nebula, for example, but the real source object probably doesn't look like that exactly.  Some of the best images I've seen are those that have been processed by people with an artistic skill.  At what point does an image move from "science" to "art"?  I contend there is not a real "point".  However I think we can agree that something has moved from artistic to ... overprocessed?


Roland Christen
 

My point was, if you have poor tracking, the underlying image is not sharp, but soft. So you can remove the stars and replace them with sharp stars, but that doesn't make the underlying image sharp. It just gives the appearance that it's sharp, when in fact the actual object that you wish to image is not.

My next comment was aimed at those who obsess over star roundness and don't actually look at the image sharpness. When you have both, then you might have APOD material.

Rolando

-----Original Message-----
From: Christopher M <mirfak@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 10, 2021 5:34 pm
Subject: Re: [ap-gto] Interesting way to image with a cheap mount

While I jest with the image of Marvin the Martian, it does bring up an interesting point:  Are not all of our processed images technically a blend of Art and Science?  Every time w Enhance Colour, Increase Contrast, Image Burn or Image Mask, False Colour assemble, etc etc, we are taking artistic liberties with the source.  True we are trying to bring out subtle details in nebula, for example, but the real source object probably doesn't look like that exactly.  Some of the best images I've seen are those that have been processed by people with an artistic skill.  At what point does an image move from "science" to "art"?  I contend there is not a real "point".  However I think we can agree that something has moved from artistic to ... overprocessed?

--
Roland Christen
Astro-Physics


psparkman@...
 

I agree with Roland.  You can always fake in the stars, but not the underlying nebula detail.  The star measures are a direct measure of the underlying detail.


Bill Long
 

Totally agree. Mounts are the most important piece of the Astrophotography package, as is using them correctly and to their full potential. Similarly good optics that are well collimated, properly thermal managed, and well focused are important as well. The better you manage and use the overall kit, the better your data is. Some people prefer to take shortcuts or the cheap route and just hope to fix it in post. I see this daily when looking through Astrobin submissions as a submitter for IOTD. Out of the roughly 9 pages of images I review per day in my queue, maybe one of two of them meet my bar on a good day. Most days I select none.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Roland Christen via groups.io <chris1011@...>
Sent: Friday, September 10, 2021 4:47 PM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Interesting way to image with a cheap mount
 
My point was, if you have poor tracking, the underlying image is not sharp, but soft. So you can remove the stars and replace them with sharp stars, but that doesn't make the underlying image sharp. It just gives the appearance that it's sharp, when in fact the actual object that you wish to image is not.

My next comment was aimed at those who obsess over star roundness and don't actually look at the image sharpness. When you have both, then you might have APOD material.

Rolando

-----Original Message-----
From: Christopher M <mirfak@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 10, 2021 5:34 pm
Subject: Re: [ap-gto] Interesting way to image with a cheap mount

While I jest with the image of Marvin the Martian, it does bring up an interesting point:  Are not all of our processed images technically a blend of Art and Science?  Every time w Enhance Colour, Increase Contrast, Image Burn or Image Mask, False Colour assemble, etc etc, we are taking artistic liberties with the source.  True we are trying to bring out subtle details in nebula, for example, but the real source object probably doesn't look like that exactly.  Some of the best images I've seen are those that have been processed by people with an artistic skill.  At what point does an image move from "science" to "art"?  I contend there is not a real "point".  However I think we can agree that something has moved from artistic to ... overprocessed?

--
Roland Christen
Astro-Physics


Dean Jacobsen
 

On Fri, Sep 10, 2021 at 04:47 PM, Roland Christen wrote:
My point was, if you have poor tracking, the underlying image is not sharp, but soft. So you can remove the stars and replace them with sharp stars, but that doesn't make the underlying image sharp. It just gives the appearance that it's sharp, when in fact the actual object that you wish to image is not.
I can't say enough good things about the mounts that the good people at Astro-Physics make.  My 1 year old Mach2 has been spectacular.  Being able to eliminate guiding has really increased my enjoyment of the hobby.  I set up the mount for every use and run a small APPM data collection bracketing the declination of my object for the night.  I can take 110 to 120 subexposures during the night and every one is useable.  No oblong stars or trailing stars. Simply wonderful performance of the mount and software.

My images aren't award winners but I have been amazed at how nice the stars look with 5 1/2 hours of unguided 3 minute images with a mount flip in the middle.

https://www.astrobin.com/ehfj0c/E/

https://www.astrobin.com/udzsan/E/

--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Roland Christen
 

You have one of the best scopes for imaging also. Nice setup overall for wide field high  res imaging.

Rolando



-----Original Message-----
From: Dean Jacobsen <deanjacobsen@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 10, 2021 9:31 pm
Subject: Re: [ap-gto] Interesting way to image with a cheap mount

On Fri, Sep 10, 2021 at 04:47 PM, Roland Christen wrote:
My point was, if you have poor tracking, the underlying image is not sharp, but soft. So you can remove the stars and replace them with sharp stars, but that doesn't make the underlying image sharp. It just gives the appearance that it's sharp, when in fact the actual object that you wish to image is not.
I can't say enough good things about the mounts that the good people at Astro-Physics make.  My 1 year old Mach2 has been spectacular.  Being able to eliminate guiding has really increased my enjoyment of the hobby.  I set up the mount for every use and run a small APPM data collection bracketing the declination of my object for the night.  I can take 110 to 120 subexposures during the night and every one is useable.  No oblong stars or trailing stars. Simply wonderful performance of the mount and software.

My images aren't award winners but I have been amazed at how nice the stars look with 5 1/2 hours of unguided 3 minute images with a mount flip in the middle.

https://www.astrobin.com/ehfj0c/E/

https://www.astrobin.com/udzsan/E/

--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/

--
Roland Christen
Astro-Physics


Dean Jacobsen
 

I love my FSQ-106 too.
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Benoit Schillings
 

well, this is basically an information theory problem. blurred images
do contain less information from a Shannon IT standpoint. the basic
info is more or less the resolution convolved with the signal to
noise, and this puts some limits to how well you can invert the
information. Basically, if you do want to deconvolve or anything
similar, the information (entropy) has to stay constant, so you are
trading resolution for signal to noise. So, yes, you could use a lot
of bad data to create some better one, but you cannot create data out
of nothing, and the resolution goes about as the third power of the
initial signal to noise (if I remember well). is this the tradeoff you
want to do ?

-- benoit

On Fri, Sep 10, 2021 at 7:41 PM Dean Jacobsen <deanjacobsen@outlook.com> wrote:

I love my FSQ-106 too.
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/


Christopher M
 

I was thinking along the lines that, taking the "artistic license" to an extreme, one can just paint a picture of a space image with paint or software.  I do not disagree with Mr Christen or others.  I consider it misrepresentation to say a heavily modified image is a true photograph when technically it is more "art".  The method Mr Christen describes reminds me of nightscapes where tracked images of stars are superimposed upon still images of landscape.  While some will try hard to produce a final image representing what they saw or felt at that location, others will do the equivalent of pasting pictures of Marvin on a Mars landscape.  I believe I fully understand how Mr Christen and others, myself included, are irked by someone saying "This is an actual photograph" when it isn't.  Unfortunately we have many people misrepresenting their images on the internet, so Kudos to people like Mr Long, Mr Christen and all who review for quality and honesty.  My own teacher has been painfully honest with my imaging attempts to date.  Garbage in => garbage out


Roland Christen
 


I love my FSQ-106 too.
That's the scope I meant. Blush

Rolando


-----Original Message-----
From: Dean Jacobsen <deanjacobsen@...>
To: main@ap-gto.groups.io
Sent: Fri, Sep 10, 2021 9:41 pm
Subject: Re: [ap-gto] Interesting way to image with a cheap mount

I love my FSQ-106 too.
--
Dean Jacobsen
Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/

--
Roland Christen
Astro-Physics


Dale Ghent
 



On Sep 11, 2021, at 11:23, Christopher M <mirfak@...> wrote:

I was thinking along the lines that, taking the "artistic license" to an extreme, one can just paint a picture of a space image with paint or software.

Topical:


Roland Christen
 


Unfortunately we have many people misrepresenting their images on the internet,
I think we're getting far away from what I wrote originally. The issue is that you do your best to get a nice looking image using tricks like I mentioned and disclosing what you did to achieve the best results possible with limited equipment. And that's what the imager did, so no problem with that. 
Where the problem comes is that someone else (not the author of the image) points to that image and proclaims that the equipment works just as good as so-called "premium" stuff, so all the people who buy premium stuff are wasting their money.

Rolando

-----Original Message-----
From: Christopher M <mirfak@...>
To: main@ap-gto.groups.io
Sent: Sat, Sep 11, 2021 10:23 am
Subject: Re: [ap-gto] Interesting way to image with a cheap mount

I was thinking along the lines that, taking the "artistic license" to an extreme, one can just paint a picture of a space image with paint or software.  I do not disagree with Mr Christen or others.  I consider it misrepresentation to say a heavily modified image is a true photograph when technically it is more "art".  The method Mr Christen describes reminds me of nightscapes where tracked images of stars are superimposed upon still images of landscape.  While some will try hard to produce a final image representing what they saw or felt at that location, others will do the equivalent of pasting pictures of Marvin on a Mars landscape.  I believe I fully understand how Mr Christen and others, myself included, are irked by someone saying "This is an actual photograph" when it isn't.  Unfortunately we have many people misrepresenting their images on the internet, so Kudos to people like Mr Long, Mr Christen and all who review for quality and honesty.  My own teacher has been painfully honest with my imaging attempts to date.  Garbage in => garbage out

--
Roland Christen
Astro-Physics


Benoit Schillings
 

totally agree Roland.

I obviously do not have any issue with image processing and other form
of deconvolution. I think that what I was pointing at is that a little
bit of degradation in the original data can be corrected by clever
software but that the tradeoff is heavy on the number of images
required.

- benoit

On Sat, Sep 11, 2021 at 8:46 AM Roland Christen via groups.io
<chris1011=aol.com@groups.io> wrote:


Unfortunately we have many people misrepresenting their images on the internet,

I think we're getting far away from what I wrote originally. The issue is that you do your best to get a nice looking image using tricks like I mentioned and disclosing what you did to achieve the best results possible with limited equipment. And that's what the imager did, so no problem with that.
Where the problem comes is that someone else (not the author of the image) points to that image and proclaims that the equipment works just as good as so-called "premium" stuff, so all the people who buy premium stuff are wasting their money.

Rolando

-----Original Message-----
From: Christopher M <mirfak@telusplanet.net>
To: main@ap-gto.groups.io
Sent: Sat, Sep 11, 2021 10:23 am
Subject: Re: [ap-gto] Interesting way to image with a cheap mount

I was thinking along the lines that, taking the "artistic license" to an extreme, one can just paint a picture of a space image with paint or software. I do not disagree with Mr Christen or others. I consider it misrepresentation to say a heavily modified image is a true photograph when technically it is more "art". The method Mr Christen describes reminds me of nightscapes where tracked images of stars are superimposed upon still images of landscape. While some will try hard to produce a final image representing what they saw or felt at that location, others will do the equivalent of pasting pictures of Marvin on a Mars landscape. I believe I fully understand how Mr Christen and others, myself included, are irked by someone saying "This is an actual photograph" when it isn't. Unfortunately we have many people misrepresenting their images on the internet, so Kudos to people like Mr Long, Mr Christen and all who review for quality and honesty. My own teacher has been painfully honest with my imaging attempts to date. Garbage in => garbage out

--
Roland Christen
Astro-Physics


Christopher M
 

My apologies for going down a garden path.  I do like Mr Ghent's summary image.  :)
Agreed, but I suspect there will always be people who will say or claim such-and-such is just as good as so-and-so.  And there will those who will actually know.  Actually I think most people will know quality when they witness it, be it a telescope mount or a car or whatever.