July 25: AR12767 in CaII K

[p_zetner]

Hello Everyone.
Here are some shots of the AR at two image scales taken in CaK. Seeing was not really good enough to support the higher magnification image and I am really pushing (beyond) the instrument limits by imaging at f63. To me, there really seems to be no additional detail visible in the higher versus lower magnification image.
The equipment used (based on a Stellarvue SV115 refractor) is marked on the photos.
Cheers.
Peter

2020-07-25-083645-0000_pipp_AS2_5x5ARL100_AI-shrp_proc.png (1.67 MiB) Viewed 991 times

2020-07-25-082821-0000_pipp_AS2_AI-shrp-ctrst_proc.png (1.4 MiB) Viewed 991 times

[rsfoto]

Hi Peter,

Great images

[dhkaiser]

Like the first one best.

[yltansg]

HI Peter,

Congrats on getting these fantastic CAK shots!!

Alfred

[EGRAY_OBSERVATORY]

Well done Peter on two superb CaK images, quite stunning..

Thanks
Terry

[DeepSolar64]

The plage activity around the spot shows up really well.

[JochenM]

Very nicely captured and processed, Peter.

Just out of curiousity; what did you use to push it all the way to f63?

[krakatoa1883]

Great shots, fine details inside the penumbra

[p_zetner]

Thanks for your kind comments everyone!
I reprocessed these shots (different video chosen for the high magnification image) with a bit of a lighter touch.
Hope you enjoy and I'd be interested to know if you have any thoughts on the new processing vs the old.
Cheers.
Peter

2020-07-25-083645-0000_pipp_AS2_5x5ARL100_AI-shrp_proc_v2.png (1.48 MiB) Viewed 938 times

2020-07-25-082821-0000_pipp_AS2_AI-shrp-ctrst_proc_v2.png (1.13 MiB) Viewed 938 times

[eroel]

Peter:
Super clean and clear CaK images, nicely processed.
Good Sunday to you and all.
Eric.

[Carbon60]

Really great images, Peter. I must admit to liking the second set better than the first.

Stu.

[marktownley]

Nice images Peter, I prefer the softer processing of the second set.

[Montana]

I like the second compared to the first because I think the contrast is much better, giving better definition of the spot details and the plage isn't blown out

Alexandra

[LTHB]

Nice set of images! I second Mark and Alexandra!

And I'd also like to ask what Barlow you used to reach f/63? (Seems to work fine for CaK. FFC?)

Frank

[p_zetner]

Thanks for the comments, everyone.
I have a tendency to get too heavy handed with the processing and then, after posting, I realize I've gone too far! I tried to rein my impulses on the second set of images.

Frank: I use a homemade barlow consisting of 5 or 4 achromatic doublets depending on whether I'm interested in 9X (f/63) or 5.7X (f/40) magnification. There are either 3 or 2 negative achromats of -120mmfl in a negative lens group followed by the filters then a -150mmfl and +160mmfl pair to comprise a positive lens group. The -120mm lenses came from Surplus Shed and the others came from Edmund Optics. For the positive lens group, I've also used a pairing of -120mmfl and 120mmfl lenses, from Surplus Shed, for a somewhat lower magnification. I can give you more details if you'd like.

All the best.
Peter

[MalVeauX]

Super capture Peter!

Very best,