Ca K image taken with the TOA 150 on April 22nd

this is the main message area for anything solar :)
Post Reply
christian viladrich
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Contact:

Ca K image taken with the TOA 150 on April 22nd

Post by christian viladrich » Thu Apr 26, 2018 8:46 pm

Hi,
This test image was taken with only fair resolution. There was some activity next to the sunspot :
Image
Christian
Christian Viladrich
Co-author of "Astronomie Planétaire"
http://www.astroplanetes.com/

User avatar
ffellah
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1927
Joined: Mon Oct 27, 2014 6:46 pm
Location: Westport, CT USA

Re: Ca K image taken with the TOA 150 on April 22nd

Post by ffellah » Fri Apr 27, 2018 12:04 am

Fantastic image and resolution

Franco

User avatar
MapleRidge
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 4956
Joined: Fri Jan 13, 2012 11:58 pm
Location: Cambray, ON Canada

Re: Ca K image taken with the TOA 150 on April 22nd

Post by MapleRidge » Fri Apr 27, 2018 1:45 am

An excellent CaK image Christian...great details :bow

Brian
Brian Colville

Maple Ridge Observatory

Cambray, ON Canada

User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 2872
Joined: Sun Nov 18, 2012 3:13 pm

Re: Ca K image taken with the TOA 150 on April 22nd

Post by Valery » Fri Apr 27, 2018 3:35 am

Christian,

This image is nearly as good as the images from April 25. The seeing here, Apr 22 is almost as good for a 6" aperture as it was later Apr 25.
For larger apertures the difference will be much more significant.

And I believe that finesse of your Barr (Materion) CaK filter is much higher than any CaK filter I ever saw (images) among amateurs. And this your filter is perfectly at the center of the CaK band. Not so with other filters. This can be seen how the supergranulation cells look like at your omages and at other images.


Valery
Last edited by Valery on Fri Apr 27, 2018 11:47 pm, edited 1 time in total.
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

User avatar
marktownley
Librarian
Librarian
Posts: 24098
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Ca K image taken with the TOA 150 on April 22nd

Post by marktownley » Fri Apr 27, 2018 5:01 am

Another brilliant image Christian.

I agree Valery about the filter being dead centre line.
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
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5266
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Ca K image taken with the TOA 150 on April 22nd

Post by Carbon60 » Fri Apr 27, 2018 5:53 am

Superb image, Christian.

Stu.
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

christian viladrich
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Contact:

Re: Ca K image taken with the TOA 150 on April 22nd

Post by christian viladrich » Fri Apr 27, 2018 6:10 pm

Thanks to all :-)
Christian Viladrich
Co-author of "Astronomie Planétaire"
http://www.astroplanetes.com/


User avatar
eroel
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3942
Joined: Mon Dec 19, 2011 10:45 pm
Location: México D.F.

Re: Ca K image taken with the TOA 150 on April 22nd

Post by eroel » Sun Apr 29, 2018 12:48 am

Christian:
Superb shot.
Best wishes,
Eric.

christian viladrich
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Contact:

Re: Ca K image taken with the TOA 150 on April 22nd

Post by christian viladrich » Mon Apr 30, 2018 9:45 am

Thanks Pedro and Eric !
Christian Viladrich
Co-author of "Astronomie Planétaire"
http://www.astroplanetes.com/

User avatar
marktownley
Librarian
Librarian
Posts: 24098
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Ca K image taken with the TOA 150 on April 22nd

Post by marktownley » Mon Apr 30, 2018 10:13 am

Hi Christian, you use the TOA very effectively here for your CaK images; are there any other scopes you have used previously that you would rate for Ca work? Thanks, Mark.
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!

christian viladrich
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Sun Jun 14, 2015 4:46 pm
Location: France
Contact:

Re: Ca K image taken with the TOA 150 on April 22nd

Post by christian viladrich » Tue May 01, 2018 4:32 pm

Hi Mark,

As you know, the problem with refractors is the spherical aberration in UV.

I have only used three refractors since I started Ca K imaging 18 years ago (time is flying ...).

- Vixen 55 mmF/8 Fluo: I started with that one.
- Taka FSQ 106 F/5 (first version ) : when I moved to the FSQ, I realized that the Vixen 55 F/8 Fluo had a huge sperical aberration in UV. When the FSQ was stopped down to 55 mm, the Ca K images were much better than with the Vixen 55 F/8 Fluo.
But ... the FSQ could not give good Ca K images at full aperture. It had to be stopped down to 80 mm or lower.
- TOA 150 : is excellent in Ca K even at full aperture. The spot diagram at 396 nm also says so ...The only limit is that the coating absorbs about 50% of the light in Ca K (for the total of the three lenses). Taka was OK to coat a lens for Ca K, but ...it meant a lot of € again.
What is nice is that a 150 nm aperture at 396 nm has the same resolution as a 250 mm aperture at 656 nm :-)

This being said... the most difficult part is to find the spherochromatism data in UV light for the various refractors available. So I am afraid I can help much :-(

I remember a post on CN describing an optical design for a refractor optimised for Ca K (two lens). This could be a way.

Another way could be to go for a 150 mm F/7 Newtonian with a coated mirror. A 50 mm Astronomik blue filter placed in front of the secondary mirror could play the role of an internal ERF. This might be the best overall option for HR Ca K imaging.
Christian Viladrich
Co-author of "Astronomie Planétaire"
http://www.astroplanetes.com/

User avatar
marktownley
Librarian
Librarian
Posts: 24098
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Ca K image taken with the TOA 150 on April 22nd

Post by marktownley » Wed May 02, 2018 5:29 am

Thanks Christian, that's useful info. I've tried a handful of scopes too, and like yourself found SA is a pain. Finding a nice CaK scope is on my bucket list. If cost was no object i'd possibly go for the TOA130. Not sure how often my seeing would let me get much more than that aperture wise.
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!

Post Reply

Who is online

Users browsing this forum: ffellah and 6 guests