2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

this is the main message area for anything solar :)
Post Reply
User avatar
H-Alpha
Almost There...
Almost There...
Posts: 598
Joined: Sun Feb 21, 2021 2:19 am
Location: Vouliagmeni (South Athens suburbs), Greece
Has thanked: 1674 times
Been thanked: 982 times

2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by H-Alpha »

Hi again,

Today (yesterday 22nd actually) everything looked perfect. Therefore, when I saw the beautiful prom at the NW not far away from the AR, I decided to try the long one... I captured for an animation for 2 hours and 40 minutes. I had great expectations!

We had no Jetstream above Greece.
2021-6-22, Jetstream.jpg
2021-6-22, Jetstream.jpg (590.73 KiB) Viewed 464 times
The SSM was showing FANTASTIC values! I had never so low values before! At a certain moment I was wondering if it will drop to zero... :lol:
As you can see the average SSM value was steadily below 1 and was even dropping below 0.5!!!
2021-6-22, SSM.jpg
2021-6-22, SSM.jpg (781.32 KiB) Viewed 464 times
Nevertheless, the following animation (I kept only the first 2h because the last forty minutes had not good image quality with few captures as exceptions) proves (I think) that what we read in SSM sometimes does not correlate at all to the image quality we get on our screen. It was obvious while capturing on my screen (surface and limb) that the image quality was deteriorating and the seeing value (in degrees) was increasing despite the drop of SSM value. The first half an hour of the animation is the best, despite the 'worst' SSM values!

And this was not due to possibly being out of focus for sure! because I was checking/correcting focus every half an hour, and also because some frames during the bad seeing period were good (temporarily good seeing), without changing the focusing.

I found all this very interesting to share with you, although I would have preferred to share a perfect 2h 40 min animation from the beginning to the end. The result follows:

Lunt130MT masked @ 102 mm, ASI290MM.
PLEASE give the long animation the time to load properly.
Image2021-6-22, Animation of NW Sun, 2h, 121 frames, 16_58_20 by H- Alpha, on Flickr

Any comment and theoretical or practical explanation of this discrepancy between SSM and Seeing/Image quality is very welcome!

I think this elusive perfect seeing is EVERYTHING! And knows how to play games very well at least in my place... :lol:

Best wishes,
Alexandros


Alexandros
Lunt 130MT+1800BF, C8 Ultima PEC+AstroSolar, Skywatcher Mount EQ6-R Pro
Baader Solar Prism, ZEISS Abbe Barlow 2x, Celestron Barlow 2x Ultima Series
ZWO ASI290MM, ZWO ASI1600MM Pro,
Greece
User avatar
marktownley
Librarian
Librarian
Posts: 42269
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20424 times
Been thanked: 10243 times
Contact:

Re: 2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by marktownley »

Nice ani and interesting about the SSM and results you got.

The SSM measures values a few KM up in the atmosphere, as the sun got lower and later in the sky were you observing over a roof of a building or something like that?


Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
User avatar
Montana
Librarian
Librarian
Posts: 34559
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17666 times
Been thanked: 8787 times

Re: 2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by Montana »

That's a beautiful animation, the prom is an excellent mover :movie

That is a very fine SSM graph, WOW!! I wish I had that. What I have learned recently is that not all seeing is the same, it is very subtle. Moments of good seeing seen in my garden are very different to moments of good seeing in someone else's country. This 'good' seeing makes a huge difference when it comes to stacking. You are not alone!

Alexandra


User avatar
davidem27
Ohhhhhh My!
Ohhhhhh My!
Posts: 148
Joined: Mon May 10, 2021 10:06 am
Location: Southern Italy
Has thanked: 81 times
Been thanked: 247 times

Re: 2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by davidem27 »

Almost 3 hours! Wow!
Your camera, while recording, was burning and melting :band

The animation is very pleasant! Congrats for the huge work.

The rotation of the disc, clearly visible, is the most interesting part of it, as well as the proms movements.


White light: Skywatcher 120 ED and Borg 76 ED with Baader Herschel Wedge and filters
H-alpha: Lunt LS50T Ha BF600, 120 ED modified by Lunt etalon. Thousand Oaks 0.9 Å Prominance filter
Calcium II K: Lunt B1200

www.volpetta.com

We are curious. We need equipment, we need seeing, we need time
User avatar
ffellah
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 11170
Joined: Mon Oct 27, 2014 6:46 pm
Location: Westport, CT USA
Has thanked: 9144 times
Been thanked: 6025 times

Re: 2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by ffellah »

A terrific animation, Alexandros. I appreciate your perseverance and focus in doing this. It is also the first one I have ever seen showing the sun’s rotation. Excellent work overall !

Franco :bow


User avatar
AJamesB
Im an EXPERT!
Im an EXPERT!
Posts: 372
Joined: Thu Jan 30, 2020 9:21 pm
Location: Maui, Hawaii
Has thanked: 1150 times
Been thanked: 630 times

Re: 2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by AJamesB »

Great animation, and great seeing! Been plagued by clouds here and wanted to get this same view but couldn't, I'm glad you did so I could see it!


Lunt ls100tha single stacked + hinode solar guider on ioptron cem26 mount
asi178mm
asi294mm
2x, 3x, and 4x telecentrics
0.6x and 0.4x telecompressors
User avatar
minhlead
Almost There...
Almost There...
Posts: 682
Joined: Sun Apr 25, 2021 9:36 pm
Location: Ha Noi, Vietnam
Has thanked: 737 times
Been thanked: 1104 times
Contact:

Re: 2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by minhlead »

H-Alpha wrote: Wed Jun 23, 2021 2:44 am Hi again,

Today (yesterday 22nd actually) everything looked perfect. Therefore, when I saw the beautiful prom at the NW not far away from the AR, I decided to try the long one... I captured for an animation for 2 hours and 40 minutes. I had great expectations!

We had no Jetstream above Greece.
2021-6-22, Jetstream.jpg

The SSM was showing FANTASTIC values! I had never so low values before! At a certain moment I was wondering if it will drop to zero... :lol:
As you can see the average SSM value was steadily below 1 and was even dropping below 0.5!!!
2021-6-22, SSM.jpg

Nevertheless, the following animation (I kept only the first 2h because the last forty minutes had not good image quality with few captures as exceptions) proves (I think) that what we read in SSM sometimes does not correlate at all to the image quality we get on our screen. It was obvious while capturing on my screen (surface and limb) that the image quality was deteriorating and the seeing value (in degrees) was increasing despite the drop of SSM value. The first half an hour of the animation is the best, despite the 'worst' SSM values!

And this was not due to possibly being out of focus for sure! because I was checking/correcting focus every half an hour, and also because some frames during the bad seeing period were good (temporarily good seeing), without changing the focusing.

I found all this very interesting to share with you, although I would have preferred to share a perfect 2h 40 min animation from the beginning to the end. The result follows:

Lunt130MT masked @ 102 mm, ASI290MM.
PLEASE give the long animation the time to load properly.
Image2021-6-22, Animation of NW Sun, 2h, 121 frames, 16_58_20 by H- Alpha, on Flickr

Any comment and theoretical or practical explanation of this discrepancy between SSM and Seeing/Image quality is very welcome!

I think this elusive perfect seeing is EVERYTHING! And knows how to play games very well at least in my place... :lol:

Best wishes,
Alexandros
Great animation, Alex. On closer inspection of your video. I still think it's probably focus shifting due to temperature change instead of seeing messing up the sharpness of your video. Since the sharpness has somekind of gradual decrease through the video, suggesting the focus is continuously going off. If it was seeing you would see the focus jumping in and out (focus chasing). Like this.
Image
You said you are refocusing every 30 minutes. How did you refocus? (By hand or by electric focuser). If you are using hands and your focuser is very sensitive then there's a possibility of focuser slipping due to angle change (the focuser slipped past optimal focus point due to gravity and the weight of the optical train behind the focuser. Things get worse when the scope track sun higher in the sky).


Minh.
Loves from Viet Nam <3
My gear:
Scope: SkyRover (Kunming Optics) 152mm F/6 Doublets
Mount: JTW Tridents GTR
Camera:
PlayerOne Apollo M-Max
Quark Chromosphere Doublestacked with PST etalon
User avatar
minhlead
Almost There...
Almost There...
Posts: 682
Joined: Sun Apr 25, 2021 9:36 pm
Location: Ha Noi, Vietnam
Has thanked: 737 times
Been thanked: 1104 times
Contact:

Re: 2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by minhlead »

Also, I can see that your surface is flickering. Probably due to not normalize well between frames. Try PixInsight batch linear fit. It would equalize the frames and eliminate the flickering that we're seeing here.


Minh.
Loves from Viet Nam <3
My gear:
Scope: SkyRover (Kunming Optics) 152mm F/6 Doublets
Mount: JTW Tridents GTR
Camera:
PlayerOne Apollo M-Max
Quark Chromosphere Doublestacked with PST etalon
User avatar
H-Alpha
Almost There...
Almost There...
Posts: 598
Joined: Sun Feb 21, 2021 2:19 am
Location: Vouliagmeni (South Athens suburbs), Greece
Has thanked: 1674 times
Been thanked: 982 times

Re: 2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by H-Alpha »

Thanks a lot James and Minh for your kind words!
minhlead wrote: Wed Jun 23, 2021 11:27 pm
Great animation, Alex. On closer inspection of your video. I still think it's probably focus shifting due to temperature change instead of seeing messing up the sharpness of your video. Since the sharpness has somekind of gradual decrease through the video, suggesting the focus is continuously going off. If it was seeing you would see the focus jumping in and out (focus chasing). Like this.
Image
You said you are refocusing every 30 minutes. How did you refocus? (By hand or by electric focuser). If you are using hands and your focuser is very sensitive then there's a possibility of focuser slipping due to angle change (the focuser slipped past optimal focus point due to gravity and the weight of the optical train behind the focuser. Things get worse when the scope track sun higher in the sky).
If there is a focusing issue Minh, then I think this is not due to focus per se, but to bad seeing not allowing better focus. In a while I will post the results of today and there you can see that the seeing jumping in and out as you say! :-)

I have a motorized focuser (Sesto Senso), so I am pretty sure the focus is ok.

How are you compensating for temperature changes? Automatically with some routine of your own? remotely by the office? ;-)

Coming to flickering, you are absolutely right. Because the animations last a very long time and the sun is going down Firecapture is trying to keep "auto histogram max", but sometimes I do this manually with exposure in-between captures, so that the Gain does not reach high values. This is should be my problem, as well as that I have not find a way to normalize exposure in the processing. PixInsight looks great from your results and from what I have read, but it is not for free... So I am hoping to find a free solution. If not, I may have to go for it...

Thanks for all your precious comments.
Best wishes,
Alexandros


Alexandros
Lunt 130MT+1800BF, C8 Ultima PEC+AstroSolar, Skywatcher Mount EQ6-R Pro
Baader Solar Prism, ZEISS Abbe Barlow 2x, Celestron Barlow 2x Ultima Series
ZWO ASI290MM, ZWO ASI1600MM Pro,
Greece
User avatar
minhlead
Almost There...
Almost There...
Posts: 682
Joined: Sun Apr 25, 2021 9:36 pm
Location: Ha Noi, Vietnam
Has thanked: 737 times
Been thanked: 1104 times
Contact:

Re: 2h Animation of NW Sun, Discrepancy between SSM-Seeing, 22-6-2021

Post by minhlead »

H-Alpha wrote: Thu Jun 24, 2021 12:10 am Thanks a lot James and Minh for your kind words!
minhlead wrote: Wed Jun 23, 2021 11:27 pm
Great animation, Alex. On closer inspection of your video. I still think it's probably focus shifting due to temperature change instead of seeing messing up the sharpness of your video. Since the sharpness has somekind of gradual decrease through the video, suggesting the focus is continuously going off. If it was seeing you would see the focus jumping in and out (focus chasing). Like this.
Image
You said you are refocusing every 30 minutes. How did you refocus? (By hand or by electric focuser). If you are using hands and your focuser is very sensitive then there's a possibility of focuser slipping due to angle change (the focuser slipped past optimal focus point due to gravity and the weight of the optical train behind the focuser. Things get worse when the scope track sun higher in the sky).
If there is a focusing issue Minh, then I think this is not due to focus per se, but to bad seeing not allowing better focus. In a while I will post the results of today and there you can see that the seeing jumping in and out as you say! :-)

I have a motorized focuser (Sesto Senso), so I am pretty sure the focus is ok.

How are you compensating for temperature changes? Automatically with some routine of your own? remotely by the office? ;-)

Coming to flickering, you are absolutely right. Because the animations last a very long time and the sun is going down Firecapture is trying to keep "auto histogram max", but sometimes I do this manually with exposure in-between captures, so that the Gain does not reach high values. This is should be my problem, as well as that I have not find a way to normalize exposure in the processing. PixInsight looks great from your results and from what I have read, but it is not for free... So I am hoping to find a free solution. If not, I may have to go for it...

Thanks for all your precious comments.
Best wishes,
Alexandros
PI is free for trial for 1 month. I am compensating the focus by my own script (Sharpcap does not support temp comp with my focuser) and remoting the observatory from work does not allow me to refocus correctly via live feed.


Minh.
Loves from Viet Nam <3
My gear:
Scope: SkyRover (Kunming Optics) 152mm F/6 Doublets
Mount: JTW Tridents GTR
Camera:
PlayerOne Apollo M-Max
Quark Chromosphere Doublestacked with PST etalon
Post Reply