HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

this is the main message area for anything solar :)
Post Reply
christian viladrich
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 2145
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Has thanked: 1 time
Been thanked: 2703 times
Contact:

HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by christian viladrich »

Dear All,

Here are some more images taken from 2930 m high at St Véran site with the 300 mm solar telescope. The seeing conditions oscillated continuously from very bad to excellent.
The first image was taken in G band (430 nm FWHM 1.9 nm). The resolution is limited by the 300 mm aperture of the scope. There are many filigrees in the intergranular region embeded in the group of pores.
Image

The second image was taken in K-line (which is not Ca K ..) at 396 nm FWHM 10 nm. This is my very first diffraction limited image taken with the 300 mm in this wavelength :-)
Image

The resolution is a tad higher compared to 430 nm. The filigrees are also visible, with some more contrast.

Meanwhile, the area of AR2720, also taken at 396 nm, was crowded with filigrees :
Image
Clear skies !
Christian


Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
User avatar
marktownley
Librarian
Librarian
Posts: 42131
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20240 times
Been thanked: 10111 times
Contact:

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by marktownley »

Crazily excellent images Christian! You need a bigger scope ;)


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
eroel
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 9389
Joined: Mon Dec 19, 2011 10:45 pm
Location: México D.F.
Been thanked: 4883 times

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by eroel »

Christian:
Superb shots.
Best regards,
Eric.


User avatar
ffellah
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 11115
Joined: Mon Oct 27, 2014 6:46 pm
Location: Westport, CT USA
Has thanked: 9074 times
Been thanked: 5977 times

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by ffellah »

The resolution is incredible, Christian !

Franco


bart1805
Almost There...
Almost There...
Posts: 636
Joined: Mon Feb 06, 2017 9:04 pm
Location: The Netherlands
Been thanked: 1 time

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by bart1805 »

Dream like images, just spectacular!


christian viladrich
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 2145
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Has thanked: 1 time
Been thanked: 2703 times
Contact:

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by christian viladrich »

Thanks to all :-)
Here is an image of the observing site :
Image


Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
User avatar
krakatoa1883
Almost There...
Almost There...
Posts: 1041
Joined: Sat Jun 11, 2016 9:41 am
Location: Mediolanum
Has thanked: 153 times
Been thanked: 496 times

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by krakatoa1883 »

For my location 0.3 arcsecs are science fiction :lol:

15 frames only for each of the images?


Raf
My solar images and reports with articles on solar equipment
User avatar
pedro
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 12236
Joined: Sun May 01, 2016 8:26 pm
Location: Portugal
Has thanked: 14 times
Been thanked: 6556 times
Contact:

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by pedro »

Outstanding images Christian. I agree with Mar, you need a bigger telescope

Where did you get the G band filter?


christian viladrich
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 2145
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Has thanked: 1 time
Been thanked: 2703 times
Contact:

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by christian viladrich »

Thanks Raf and Pedro !
Raf : yes, there are only 15 frames in each stack. The IMX174 is an amazing sensor.
Pedro : this is a filter from Andover. It is listed in the "surplus". Indeed, I think that a 400 mm would be appropriate to the conditions up there.


Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
User avatar
MalVeauX
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1853
Joined: Tue May 09, 2017 7:58 pm
Location: Florida
Has thanked: 1142 times
Been thanked: 1329 times

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by MalVeauX »

Super resolution, always a pleasure! :bow

Very best,


User avatar
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 14175
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK
Has thanked: 8355 times
Been thanked: 8103 times

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by Carbon60 »

Absolutely remarkable images, Christian.

Do you drive to the site, or is it accessible only by cable car?

Stu.


H-alpha, WL and Ca II K imaging kit for various image scales.
Fluxgate Magnetometers (1s and 150s Cadence).
Radio meteor detector.
More images at http://www.flickr.com/photos/solarcarbon60/
christian viladrich
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 2145
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Has thanked: 1 time
Been thanked: 2703 times
Contact:

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by christian viladrich »

Thanks Marty and Stu :-)
It's easier to get up there with a 4WD. There is no cable car.


Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
Derek Klepp
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 12900
Joined: Wed Oct 19, 2011 10:02 am
Been thanked: 171 times

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by Derek Klepp »

Great pics and great site.Nothing that high here in Australia.


User avatar
Montana
Librarian
Librarian
Posts: 34526
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17521 times
Been thanked: 8763 times

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by Montana »

Wow!!!!!!! mouth watering and I am dribbling :lol:

Last night I booked a holiday only 20km from Pic du Midi :hamster: I wonder what will be filling the car with on that holiday :)

Alexandra


bart1805
Almost There...
Almost There...
Posts: 636
Joined: Mon Feb 06, 2017 9:04 pm
Location: The Netherlands
Been thanked: 1 time

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by bart1805 »

Hi Christian, like Raf each time I see your pictures it is a surprise that you stack such a small amount of frames. It is quite the opposite compared to my own workflow, but your pictures inspired me to go through some old data and use far less frames than I usually do. And I am surprised. I can use less LR deconvolution and about the same or a bit more unsharp masking to create better results when using these numbers of frames:
15 - 20 frames in white light / Solar continuum
30 - 50 frames in Cak
45 to 70 frames in H-alpha.
Thanks again for the beautiful pictures and for the inspiration. CS! Bart.


christian viladrich
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 2145
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Has thanked: 1 time
Been thanked: 2703 times
Contact:

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by christian viladrich »

Thanks Derek, Alexandra and Bart :-)

Alexandra, it is possible to spend a night at the Pic du Midi observatory and have access to a 50 cm Dobsonian telescope. You have to book in advance.

Bart, you have a keen eye ;-)
The number of images you have to stack depends on the S/N of each image, which depends on :
- the full well capacity of the sensor (= max number of electrons by pixel), the higher the better. The IMX174 is excellent in this respect.
- the seeing : better seeing means better S/N.

Then, if the quality of the stacked image is better, its contrast is higher, meaning the processing can be less agressive.

Typically, I have :
- 7 to 30 frames in WL (gain of the camera set to the minimum),
- 30 to 60 frames in Ca K ,
- 200 to 300 images in Ha (gain of the camera set to high).


Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
bart1805
Almost There...
Almost There...
Posts: 636
Joined: Mon Feb 06, 2017 9:04 pm
Location: The Netherlands
Been thanked: 1 time

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by bart1805 »

Thanks Christian. I try to image H-alpha with low gain, so maybe that is the reason I could use fewer frames. But will try it with high gain and more frames to stack: shorter exposure time so better freezing of the seeing.
Gamma is always neutral when you image in these three wavelengths?
CS! Bart.


christian viladrich
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 2145
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Has thanked: 1 time
Been thanked: 2703 times
Contact:

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by christian viladrich »

Bart,
I dont' remember the sensor you have. If you have a CMOS sensor with low read noise (IMX174, IMX290, etc), then the following apply to set the gain when the level of ligh is low (i.e. Ha imaging) :
1) Set the exposure time to the value giving the max fps of the camera (e.g. if the max fps is 150 fps, then you set the exposure time to 6.6 ms).
If the camera max fps is low, then set the exposure time to about 6 - 8 ms (the shorter the better).
2) Set the gain in order to have the max value of the histogram to about 70to 80%.
This is all :-)

I use gamma = 1 for all types of images except prominences. It is better to tune the gamma during processing rather than during acquisition.


Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
bart1805
Almost There...
Almost There...
Posts: 636
Joined: Mon Feb 06, 2017 9:04 pm
Location: The Netherlands
Been thanked: 1 time

Re: HR images taken at 396 and 430 nm on August 24 with the 300 mm solar scope

Post by bart1805 »

Thanks Christian!
I use the Grasshopper version with the IMX174 sensor. So for one thing, I can't blame the camera if I compare my images with yours. (-;


Post Reply