Search found 42 matches

by LTHB
Mon Nov 19, 2018 9:44 pm
Forum: Solar Scope Modifications
Topic: optical contact experiments? Anybody?
Replies: 3
Views: 67

Re: optical contact experiments? Anybody?

I have no experience with home-brewed etalons, but Baader says on their webpage that their filter glass is "polished plane to a quarter wavelength on both sides", which makes me a bit sceptical if two Baader filters give a working etalon (allthough I am a big fan of tinkering with optical components...
by LTHB
Sun Oct 14, 2018 7:11 pm
Forum: Solar Astronomy Shop and Swap
Topic: "Astronomie Solaire" - New (French) book on Solar Observation now available
Replies: 18
Views: 611

Re: "Astronomie Solaire" - New (French) book on Solar Observation now available

Nice! I would also appreciate an English version of your book as unfortunately my broken French is not good enough for really reading books.

Regards,

Frank
by LTHB
Sun Oct 14, 2018 7:06 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: For Science / Math Lovers: Measurement of a Solar Filament Temperature.
Replies: 6
Views: 915

Re: For Science / Math Lovers: Measurement of a Solar Filament Temperature.

Marvelous! Reading this almost makes me want to seek early retirement so I can pursue small science projects like this, too! Thanks also for the concise summary of the theoretical background, very interesting!

Regards,

Frank
by LTHB
Tue Oct 02, 2018 11:07 pm
Forum: This is SolarChat !!
Topic: Sharpening high resolution CaK images
Replies: 25
Views: 778

Re: Sharpening high resolution CaK images

Thanks for all the responses and suggestions! Unfortunately I won‘t be able to really appreciate and digest them before the weekend, but then I will! Till then I just wanted to share some reading material I found looking for information on the soft, blurry structures on the CaK images from the DOT: ...
by LTHB
Mon Oct 01, 2018 10:10 pm
Forum: This is SolarChat !!
Topic: Sharpening high resolution CaK images
Replies: 25
Views: 778

Sharpening high resolution CaK images

Today I found time to process some CaK videos from September 19th. Seeing was quite good, but the sky was a little hazy, transparency not really good. Working on these images I was, again, struggling with the question how much sharpening is appropriate if the aim is to depict the structures of the c...
by LTHB
Tue Sep 11, 2018 9:20 pm
Forum: This is SolarChat !!
Topic: CaK from September 4th, 2018
Replies: 2
Views: 205

CaK from September 4th, 2018

A week ago, on Sept. 4th, I could capture some CaK through a break in the clouds that lasted for a few minutes only, but the seeing was o.k. Unfortunately, after two short videos the sun was gone again before I could get a Barlow lens to get the proper focal lenght for the seeing. Processing the bet...
by LTHB
Fri Aug 31, 2018 6:44 pm
Forum: This is SolarChat !!
Topic: AR12719 High Res at 390nm, CaK and H-a in a 280mm scope.
Replies: 5
Views: 330

Re: AR12719 High Res at 390nm, CaK and H-a in a 280mm scope.

Wonderful images! It is fun and very interesting to see the same region in different wavelengths and to compare structures to see what is visible in which wavelength and how these features correlate. Thanks for showing!

Frank
by LTHB
Tue Aug 28, 2018 5:44 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: 08Aug: Spectral sweep through the Ca K line
Replies: 13
Views: 761

Re: 08Aug: Spectral sweep through the Ca K line

Hi Peter,

very instructing and useful for judging if a CaK-filter is on band or not, thanks for posting!

Frank
by LTHB
Mon Aug 27, 2018 7:38 pm
Forum: This is SolarChat !!
Topic: CaK from August 7th with ARIES-ERF
Replies: 17
Views: 677

Re: CaK from August 7th with ARIES-ERF

Hi Valery, unfortunately I did not keep the video (some GBs) for lack of space on my hard drive! The image I posted was processed from a stack of 200 frames - if you think this is still worth reprocessing I can email you the unprocessed tif-file. Next time I get the chance to capture decent CaK I wi...
by LTHB
Mon Aug 27, 2018 7:03 pm
Forum: This is SolarChat !!
Topic: A random area at the Sun chromosphere in CaK with 280mm C11
Replies: 8
Views: 313

Re: A random area at the Sun chromosphere in CaK with 280mm C11

Fantastic, Valery! As Peter said, close to the DOT pictures, as far as I can tell!

I guess you are not really serious about the "relatively poor seeing", are you? Would you mind to tell about your way of processing?

Regards,

Frank
by LTHB
Mon Aug 27, 2018 6:55 pm
Forum: This is SolarChat !!
Topic: August 16 2018 AR12718 3 bands 280mm scope.
Replies: 21
Views: 755

Re: August 16 2018 AR12718 3 bands 280mm scope.

I hope so, too! I, for one, would very much like to see them!

Frank
by LTHB
Sun Aug 26, 2018 2:07 pm
Forum: This is SolarChat !!
Topic: August 16 2018 AR12718 3 bands 280mm scope.
Replies: 21
Views: 755

Re: August 16 2018 AR12718 3 bands 280mm scope.

Hi Valery, thanks (somewhat belatedly - I was very busy last week) for the info! I am also shooting CaK at 6ms (or a little less) exposure time, but I mostly stack around 200 frames. I've never used a stack of more than 1000 frames, but I recall that Emil Kraaikamp says somewhere on his website, tha...
by LTHB
Sun Aug 26, 2018 11:42 am
Forum: This is SolarChat !!
Topic: Eliminating bad frames during stacking?
Replies: 9
Views: 364

Re: Eliminating bad frames during stacking?

If you want to exclude a couple of bad frames from stacking in Autostakkert you can also do that by deselecting them in Autostakkert: Just click through the video (loaded in Autostakkert) frame by frame (or/and use the slider to move through the video) and hit the space-bar for each bad frame. You s...
by LTHB
Sun Aug 26, 2018 10:53 am
Forum: This is SolarChat !!
Topic: CaK from August 7th with ARIES-ERF
Replies: 17
Views: 677

Re: CaK from August 7th with ARIES-ERF

Hello Christian, thanks for the suggestion! When I apply a (rather aggressive) unsharp mask only (i.e. no deconvolution) the best I get looks like this: https://c2.staticflickr.com/2/1882/44226015162_549154f95f_o.jpg Unfortunately this does not really seem to improve the image: While the difference ...
by LTHB
Mon Aug 20, 2018 10:11 am
Forum: This is SolarChat !!
Topic: A new small group - images added
Replies: 10
Views: 363

Re: A new small group

Hi Raf,

beautiful shots!

I caught the same group in CaK in late afternoon:

Image

Image

Quite interesting to see how much has changed over a few hours!

Regards,

Frank
by LTHB
Sat Aug 18, 2018 9:27 pm
Forum: This is SolarChat !!
Topic: August 16 2018 AR12718 3 bands 280mm scope.
Replies: 21
Views: 755

Re: August 16 2018 AR12718 3 bands 280mm scope.

Hi Valery,

great pictures! The CaK in particular is terrific - I haven't seen any CaK image taken with amateur equipment that comes closer to the DOT images in terms of detail and resolution!

Would you tell us what exposure time you used and how many frames you stacked?

Regards,

Frank
by LTHB
Thu Aug 16, 2018 6:24 pm
Forum: This is SolarChat !!
Topic: CaK in high resolution of August 3rd and 6th
Replies: 8
Views: 380

Re: CaK in high resolution of August 3rd and 6th

Scope was a Mewlon 210 with Lunt CaK filter, double-stacked with a yellow PST filter, Aries front ERF.

Regards,

Frank
by LTHB
Wed Aug 15, 2018 8:02 pm
Forum: This is SolarChat !!
Topic: CaK in high resolution of August 3rd and 6th
Replies: 8
Views: 380

Re: CaK in high resolution of August 3rd and 6th

Thanks, Alexandra and Mark! Rainer, you are right, the images are quite dark, certainly a lot darker than most CaK images posted here on solarchat or on CN, and I am not sure if I find them aesthetically very pleasing. However, my intention in processing them was to get a "look" similar to the CaK i...
by LTHB
Tue Aug 14, 2018 9:20 pm
Forum: This is SolarChat !!
Topic: CaK in high resolution of August 3rd and 6th
Replies: 8
Views: 380

CaK in high resolution of August 3rd and 6th

Two more CaK images from August 3rd and August 6th, and two more attempts at image processing that takes the DOT pictures as a standard.

Image

Image

Regards,

Frank
by LTHB
Mon Aug 13, 2018 10:55 am
Forum: This is SolarChat !!
Topic: Sunset Moonset on Walters Mountain + Venting Satellite
Replies: 13
Views: 503

Re: Sunset Moonset on Walters Mountain + Venting Satellite

Wonderful pictures, Derek, thanks for sharing!

Frank
by LTHB
Sat Aug 11, 2018 7:26 pm
Forum: This is SolarChat !!
Topic: CaK from August 7th with ARIES-ERF
Replies: 17
Views: 677

Re: CaK from August 7th with ARIES-ERF

Hi all, looking for a standard for correct/appropriate processing of my CaK images I browsed the webpage of the (now mothballed) Dutch Open Telescope (DOT). I found this one: http://www.staff.science.uu.nl/~rutte101/dot/albums/images/20060923-mosaic-ca.png The DOT is, of course, much bigger than our...
by LTHB
Fri Aug 10, 2018 4:15 pm
Forum: This is SolarChat !!
Topic: CaK from August 7th with ARIES-ERF
Replies: 17
Views: 677

Re: CaK from August 7th with ARIES-ERF

Hi Valery, I just sent you a PM with the unprocessed stack of the image in my first post (a tif-file). After that I just saw your post with the reprocessed image, thanks! That's really interesting and it speaks precisely to the point of my question! I have used imppg's deconvolution tool for process...
by LTHB
Fri Aug 10, 2018 12:32 am
Forum: This is SolarChat !!
Topic: CaK from August 7th with ARIES-ERF
Replies: 17
Views: 677

Re: CaK from August 7th with ARIES-ERF

Thanks, Eric and Mark! Eric, I can see why the picture looks underprocessed to you (and to Valery, too),while in fact I did quite a lot of processing: It looks slightly blurred, but I could not improve that by much. My second version: https://c1.staticflickr.com/1/859/29017337817_5044c29643_o.jpg Re...
by LTHB
Thu Aug 09, 2018 1:31 pm
Forum: This is SolarChat !!
Topic: CaK from August 7th with ARIES-ERF
Replies: 17
Views: 677

Re: CaK from August 7th with ARIES-ERF

Thanks, Alexandra and Valery! Valery, I just try to send you a PM with the unprocessed stack from Autostakkert3, but failed, probably because the file is too large (15MB). Can I send it via email? - It would be great if I could see your processing results and learn! I also just searched a little for...
by LTHB
Wed Aug 08, 2018 2:07 pm
Forum: This is SolarChat !!
Topic: CaK from August 7th with ARIES-ERF
Replies: 17
Views: 677

CaK from August 7th with ARIES-ERF

Sun is shining even in northern Germany now AND seeing was o.k. yesterday, so another rare opportunity to get the ARIES-ERF out and capture some CaK. https://c2.staticflickr.com/2/1794/43877196782_c92657b4cf_o.jpg This is the result of two afternoons trying to understand how to use imppg, i.e. decon...