Sun FD in H-Alpha and CaK 22nd of September 2021

[arnedanielsen]

Dear friends,

After a few days with clouds and rain it was nice and sunny today. I started out taking the regular FD images in H-Alpha and CaK as soon as the Sun was high enough to be viewed from my backyard. Afterwards I started a FD time-lapse recording in H-Alpha, which ran for about 75 minutes before I had to cancel the recording because of scattered clouds. I will post the resulting animation a little later. In the meantime here are the still images.

FD image in H-Alpha using a Coronado 60mm/BF15 w/Beloptik ITF, stopped down to 50mm, Baader 35nm H-Alpha and ASI 178mm mounted on a SkyWatcher SolarQuest.

Sun60FD_090454_Ha_20210922_ZWO ASI178MM(53096324)_lapl4_ap5439_out_Contrast_resize.jpg (314.77 KiB) Viewed 504 times

Sun FD in H-Alpha 22nd of September 2021

Sun60FD_090454_Ha_20210922_ZWO ASI178MM(53096324)_lapl4_ap5439_out_Contrast_Colorized_resize.jpg (334.24 KiB) Viewed 504 times

Sun FD in H-Alpha 22nd of September 2021 - colorized



FD image in CaK using a William Optics ZenithStar 61II, stopped down to 46mm, Lunt CaK 1200 module, Coronado 2x CeMax and ASI 183mm camera mounted on a SkyWatcher SolarQuest.

SunCaK60_080721_CaK_(3934nm)_20210922_ZWO ASI183MM_lapl4_ap7285_out_Contrast_resize.jpg (204 KiB) Viewed 504 times

Sun FD in CaK 22nd of September 2021

SunCaK60_080721_CaK_(3934nm)_20210922_ZWO ASI183MM_lapl4_ap7285_out_Contrast_Colorized_resize.jpg (226.84 KiB) Viewed 504 times

Sun FD in CaK 22nd of September 2021 - colorized



Click on links to view full size images.

Thanks for looking and best regards,
Arne

[EGRAY_OBSERVATORY]

Thanks Arne for your excellent FD's of today

Terry

[ffellah]

I agree with Terry, your discs are excellent Arne. Well done !

Franco

[DeepSolar64]

Absolutely beautiful full discs Arne! I love the second colored Ha image. The image is very even and the color is wonderful! The detail is also very good too. It looks very natural. To be any more natural it would have to be Ha red!

James

[arnedanielsen]

Thank you very much Terry, Franco and James for your kind words! Much appreciated!

Best regards,
Arne

[pedro]

Great FD images Arne

[arnedanielsen]

Dear friends,

Here's the resulting time-lapse from yesterdays session. Not to much activity going on and it was cut a bit short because of clouds, but I'm overall happy with how it turned out.

Equipment used was the Coronado 60mm/BF15 w/Beloptik ITF, stopped down to 50mm, Baader 35nm H-Alpha and ASI 178mm mounted on a SkyWatcher SolarQuest.
The time-lapse was created from 154 recordings each consisting of 400 frames forced to a framerate of 20fps and a cadence of one recording per 30 seconds. The best 200 from each recording was then stacked in AutoStakkert!3, aligned, sharpened and normalized in ImPPG before scaling down to 50% and creating the resulting animation in PIPP with 12 fps effectively compressing the 1h 17m down to 12 seconds.
Just need to mount the scope on a Eq-Mount for this to avoid field rotation.





Click on links to see the animation.

Thanks and best regards,
Arne

[arnedanielsen]

Thank you VM, Pedro!

Best regards,
Arne

[Montana]

Wow!! superb images, but the animation is out of this world, it is so smooth!! how do you get this without flickering? amazing!



Alexandra

[marktownley]

Good to see the disks back Arne!

[Ivan]

Arne, this is a wonderful animation, there are so many details that change! It was such a pleasure to look at each piece and then move on and see new changes. I join Alexandra's question, how did you achieve the same brightness in all frames?

Ivan

[EGRAY_OBSERVATORY]

Hello Arne, the animations are fabulous for a FD capture. The field rotation adds a little interest to the whole surface-detail that can clearly be seen.

I would imagine that these were taken in good seeing conditions over the period of time and I can just see some very little atmospheric-changes, but not that much...

Well done and thanks for sharing

Terry

[arnedanielsen]

Thank you very Alexandra, Mark, Ivan and Terry for all your kind comments!

The seeing was just average, but the transmission good and very consistent throughout the recording - at least until the scattered clouds appeared. I used the "Normalize brightness level" in ImPPG, but I'm not sure how important this was because the conditions where very stable. Sharpening, contrast stretching and alignment was also done in ImPPG. Colorization for the color version was done in PhotoShop and cropping, resize and creating the animation in PIPP. The published animation is at 50% resolution, but I can try to publish it if there are interest.

In general I think FD low-res animations like these are quite forgiving when it comes to seeing. One "trick" I do is to force the max fps to be quite low to "distribute" the images across the recording period. I believe this increases the chances for at least some good frames in each recording compared to a short burst, which might hit or miss periods of good seeing. For this animation I recorded for 20 seconds and then idle for 10 seconds to ensure that everything was saved before I started on the next recording. However, at this low fps I can see that the 10 seconds of idling was not necessary and I could have done either 20 second recordings back to back or increased the each recording to 30 second.

Ideally I would run at max fps with no delays between each recording to maximize the chance of getting good data, but this would put huge demands on CPU speed, disk speed and disk space both during capture and during post-processing.

Best regards,
Arne

[rigel123]

Those came out great Arne and that was a super smooth animation!

[Carbon60]

Excellent FDs and animations, Arne. Very nicely done.

Stu.

[Montana]

Very interesting Arne, I have never come across the 'normalise image brightness' before. I need to go and have a look. Is that done during sharpening, or is that part of the 'image align' sequence?

Alexandra

[arnedanielsen]

Thank you very much Warren and Stu!

Alexandra: The normalize image brightness can be found under settings.

ImPPPGSettings.PNG (77.93 KiB) Viewed 422 times

ImPPPGNormalize.PNG (10.94 KiB) Viewed 422 times

You could of course do something similar in PIPP or PhotoShop.

Best regards,
Arne

[Montana]

I see, so it looks like it is nromalising the histogram of that image, not normalising it to all the others in the batch. Interesting, I was hoping it was part of the batch processing of image alignment to get them all the same brightness. Food for thought though

Alexandra

[arnedanielsen]

I see, so it looks like it is nromalising the histogram of that image, not normalising it to all the others in the batch. Interesting, I was hoping it was part of the batch processing of image alignment to get them all the same brightness. Food for thought though

Alexandra

Yes, ImPPPG is normalizing each image individually. To normalize the images across the sequence (in respect to each other) you could use a tool like GBDeflicker:
https://www.granitebaysoftware.com/prod ... ctgbd.aspx

Best regards,
Arne

[marios i.]

Wonderful images!

[arnedanielsen]

Thank you very much Marios!

Best regards,
Arne