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Transit of Mercury in the Spicule Layer. Phil took this great image with his Quantum 6 Scope, Solar Spectrum etalon and PGR Camera.
Welcome to Solar Chat! The best forum for Solar Astronomy
Moving forward from solar cycle 24 to 25
Search found 564 matches
- Wed Nov 13, 2019 8:08 pm
- Forum: This is SolarChat !!
- Topic: Mercury Transit
- Replies: 11
- Views: 172
Re: Mercury Transit
Well done !
- Wed Nov 13, 2019 8:07 pm
- Forum: This is SolarChat !!
- Topic: Mercury transit and proms
- Replies: 16
- Views: 218
Re: Mercury transit and proms
Excellent indeed, congratulations !
- Wed Nov 13, 2019 8:06 pm
- Forum: This is SolarChat !!
- Topic: Mercury Solar transit 11th of November 2019.
- Replies: 13
- Views: 166
Re: Mercury Solar transit 11th of November 2019.
Beautifull images Eric, well done !
- Tue Nov 12, 2019 7:58 pm
- Forum: This is SolarChat !!
- Topic: Autostakkert2 flats issue
- Replies: 8
- Views: 172
Re: Autostakkert2 flats issue
The flat image is to be calculated by AS.
So, first record the flat as an AVI (or SER) file.
Then process this AVI or SER file in AS to calculate the flat image (PNG or TIF).
Then use this flat image in AS.
So, first record the flat as an AVI (or SER) file.
Then process this AVI or SER file in AS to calculate the flat image (PNG or TIF).
Then use this flat image in AS.
- Sat Nov 09, 2019 7:16 pm
- Forum: Solar Scope Modifications
- Topic: PST mod on a C14
- Replies: 11
- Views: 602
Re: PST mod on a C14
It would also need large pixel size and / or a focal reducer after the etalon. Otherwise, the image scale would be way too large.
- Fri Nov 08, 2019 1:39 pm
- Forum: Solar Scope Modifications
- Topic: PST mod on a C14
- Replies: 11
- Views: 602
Re: PST mod on a C14
Here is the sweet spot radius depending on the max CWL allowed and on the focal length of the telescope:


- Fri Nov 08, 2019 1:13 pm
- Forum: Solar Scope Modifications
- Topic: PST mod on a C14
- Replies: 11
- Views: 602
Re: PST mod on a C14
Indeed,in a telecentric system: - F/30 and above is "good" with mica-spaced etalons: http://astrosurf.com/viladrich/astro/instrument/solar/FWHM-N.JPG - F/50 and above is needed for air-spaced etalons : http://astrosurf.com/viladrich/astro/instrument/solar/Fig7.82-air-spaced-etalon-FWHM-FD.jpg In a c...
- Mon Oct 14, 2019 9:19 pm
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: Strehl ratio for a Celestron C11
- Replies: 7
- Views: 306
Re: Strehl ratio for a Celestron C11
What aperture did you use to take this image ?
- Mon Oct 14, 2019 6:36 pm
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: Strehl ratio for a Celestron C11
- Replies: 7
- Views: 306
Re: Strehl ratio for a Celestron C11
Here are some actual interferometric measurements (HASO) of the Strelh ratio of various C11 OTA (EdgeHD or not) at 473 nm : https://www.airylab.com/contenu/mesures/astro/rapport%202015-35003-a.pdf https://www.airylab.com/contenu/mesures/astro/rapport%202012-33001.pdf https://www.airylab.com/contenu/...
- Tue Sep 17, 2019 8:14 am
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: What do you think is the most versatile high resolution solar telescope design?
- Replies: 43
- Views: 2741
Re: What do you think is the most versatile high resolution solar telescope design?
Hello Valery, Going back to the initial question of this post, and after the tests recently done à St Véran, I agree that the combination of a large ERF and a reflecting telescope is the best HR solar telescope in large diameter. The Cassegrain configuration is indeed very attractive. Best regards C...
- Mon Sep 16, 2019 4:43 pm
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: What do you think is the most versatile high resolution solar telescope design?
- Replies: 43
- Views: 2741
Re: What do you think is the most versatile high resolution solar telescope design?
Hi, I would like to go back to the question of spherochromatism which is inherent to the Schmidt- Cassegrain design. As I have already said, this is nothing new, optics beeing optics. Let's see what Celestron wrote in their White Paper : https://s3.amazonaws.com/celestron-site-support-files/support_...
- Sun Sep 15, 2019 2:12 pm
- Forum: This is SolarChat !!
- Topic: H-alpha 31 august, 7 inch Intes, reflections and a BF30.
- Replies: 15
- Views: 619
Re: H-alpha 31 august, 7 inch Intes, reflections and a BF30.
Hello Bart,
This is a quite good image. Getting rid of these reflections is quite tricky. Keep us posted !
Christian
This is a quite good image. Getting rid of these reflections is quite tricky. Keep us posted !
Christian
- Sun Sep 15, 2019 12:38 pm
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: What do you think is the most versatile high resolution solar telescope design?
- Replies: 43
- Views: 2741
Re: What do you think is the most versatile high resolution solar telescope design?
Yes, indeed !
Thanks Bart
Thanks Bart
- Sun Sep 15, 2019 11:54 am
- Forum: Commercial Solar Filters/Cameras/Hardware
- Topic: What do you think is the most versatile high resolution solar telescope design?
- Replies: 43
- Views: 2741
Re: What do you think is the most versatile high resolution solar telescope design?
Hello langleif2, Spherochromatism in Schmidt-Cassegrain is nothing new. You can open any good books on telescope optics to get some information on it. This is just basic optics. You can read for example the two books I co-authored with some friends (unfortunately in French language for now) ;-) Ther...
- Sun Sep 15, 2019 11:24 am
- Forum: Solar Scope Modifications
- Topic: A big solar newton for ultra narrowband imaging, possible?
- Replies: 30
- Views: 1259
Re: A big solar newton for ultra narrowband imaging, possible?
I also have the TS concenter. It is indeed quite good to align the secondary mirror of the 300 mm solar Newtonian.
- Sun Sep 15, 2019 11:23 am
- Forum: Solar Scope Modifications
- Topic: A big solar newton for ultra narrowband imaging, possible?
- Replies: 30
- Views: 1259
Re: A big solar newton for ultra narrowband imaging, possible?
Hello langleif2, This is a textbook example of loss of information in a communication process : A tells a story to B, which B repeats it to C, etc. After a short while the story becomes quite another story :-) So here the actual story : Every year, we have a solar gathering at Serbannes (France). Ne...
- Sat Sep 14, 2019 8:04 pm
- Forum: Solar Scope Modifications
- Topic: Budget scope for visual
- Replies: 18
- Views: 696
Re: Budget scope for visual
430 nm filters are available at Edmund Optics with 10, 25 and 50 nm FWHM, and also at Andover Optics (2 nm FWHM).
- Tue Sep 10, 2019 7:11 am
- Forum: Solar Scope Modifications
- Topic: A big solar newton for ultra narrowband imaging, possible?
- Replies: 30
- Views: 1259
Re: A big solar newton for ultra narrowband imaging, possible?
Hello lanleif2, thanks for this clarification. I am afraid you were a bit mislead. I know rather well AiryLab and MCM. Alex do so since he is the one you got his 250 mm coated by MCM. So far, this is the larger Newtonian telescope with such a coating on the mirror. This telescope and MCM coating is ...
- Sun Sep 08, 2019 7:30 pm
- Forum: Solar Scope Modifications
- Topic: A big solar newton for ultra narrowband imaging, possible?
- Replies: 30
- Views: 1259
Re: A big solar newton for ultra narrowband imaging, possible?
The DOT is a Gregorian telescope, not a Netwonian. This is a huge difference and explains why a cooled diaphragm can be installed at the primary focus. Remember that in a Gregorian telescope the focus of the primary mirror is in front of the secondary mirror, not behind. This makes thing much easier...
- Fri Sep 06, 2019 7:14 am
- Forum: Solar Scope Modifications
- Topic: A big solar newton for ultra narrowband imaging, possible?
- Replies: 30
- Views: 1259
Re: A big solar newton for ultra narrowband imaging, possible?
We were on top of a mountain, 2930 m altitude. Ambient temperature was from 2°C to about 15°C.
So an increase of 10°C is huge. Basically, a delta of more than 2°C between ambient air and an optical part is detrimental to the seeing.
So an increase of 10°C is huge. Basically, a delta of more than 2°C between ambient air and an optical part is detrimental to the seeing.
- Thu Sep 05, 2019 6:48 pm
- Forum: Solar Scope Modifications
- Topic: A big solar newton for ultra narrowband imaging, possible?
- Replies: 30
- Views: 1259
Re: A big solar newton for ultra narrowband imaging, possible?
Unfortunately, these tests proved that this idea was a dead end. For Ca K imaging with my TOA150, the 50 mm internal ERF is 33% of the diameter of the objective. I have no internal turbulence. With the 300 m Newtonian of Alex, the ratio is 16%. Now, we can say this is too low... Maybe, another facto...
- Fri Aug 30, 2019 8:32 am
- Forum: Solar Scope Modifications
- Topic: Removing mirror’s coating
- Replies: 6
- Views: 397
Re: Removing mirror’s coating
Hello STu,
Thanks a lot for your input.
Could you tell us a little bit about the differences between iron perchloride et HCl ? I understood than the first one is less agressive ?
Thanks a lot for your input.
Could you tell us a little bit about the differences between iron perchloride et HCl ? I understood than the first one is less agressive ?
- Sat Aug 24, 2019 3:34 pm
- Forum: This is SolarChat !!
- Topic: HR images taken with the N300 on August 21
- Replies: 9
- Views: 460
Re: HR images taken with the N300 on August 21
Thanks to all :-)
I like the fourth one too !
I like the fourth one too !
- Sat Aug 24, 2019 3:33 pm
- Forum: This is SolarChat !!
- Topic: 24Aug19 - Some fibrils with C11
- Replies: 14
- Views: 526
Re: 24Aug19 - Some fibrils with C11
Well done Alfred !
- Thu Aug 22, 2019 6:06 pm
- Forum: This is SolarChat !!
- Topic: HR images taken with the N300 on August 21
- Replies: 9
- Views: 460
HR images taken with the N300 on August 21
The Internet is back at St Véran .. Here is a set of pictures taken on August 21 with the 300 mm Newtonian and the 396-5 nm filter. Let's start with a region close to the Eastern limb, with many faculae and darker areas. http://www.astrosurf.com/viladrich/astro/soleil/wl/2019/21August2019-8h03minUT-...