Search found 251 matches

by krakatoa1883
Fri Sep 21, 2018 10:27 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 17
Views: 290

Re: Experimenting calcium imaging with small refractors

Very informative table. Looking at the spot diagrams for the g-line (light blue) it seems that only few of the objectives are fairly corrected for this wavelength (calcium H and K lines should give even worse results) but of course some are better than others. Note that semi-apo designs are not much...
by krakatoa1883
Thu Sep 20, 2018 8:04 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 17
Views: 290

Re: Experimenting calcium imaging with small refractors

Peter made some excellent images using a 115mm triplet, may be with optics similar to Tecnosky apo but I am not sure. I had this triplet in its first version with a different focuser but same objective and I remember it was really good. At the time I was not interested in calcium imaging but I am no...
by krakatoa1883
Thu Sep 20, 2018 2:30 pm
Forum: This is SolarChat !!
Topic: Sept 16th Sun and Yard Views
Replies: 8
Views: 99

Re: Sept 16th Sun and Yard Views

Nice set o images and beautiful colors in your yard!
by krakatoa1883
Thu Sep 20, 2018 7:31 am
Forum: This is SolarChat !!
Topic: Sol in CaK from the 14th and in Ha from the 16th of September 2018.
Replies: 9
Views: 128

Re: Sol in CaK from the 14th and in Ha from the 16th of September 2018.

Beautiful, Eric, that snake on the right side is impressive!
by krakatoa1883
Thu Sep 20, 2018 7:30 am
Forum: This is SolarChat !!
Topic: Exploding arch prom from 9/19
Replies: 11
Views: 130

Re: Exploding arch prom from 9/19

Impressive, well captured!
by krakatoa1883
Wed Sep 19, 2018 7:56 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 17
Views: 290

Re: Experimenting calcium imaging with small refractors

Fine images, Pedro. Your image with the TMB80 F/11.7 is quite good and is representative of the resolution that can actuallly be reached with a 80 mm in Ca K. On my side, I had found that the (old) Taka FSQ 106 was good when stopped down to 80 mm. thanks Christian, I had an excellent sample of Sky 9...
by krakatoa1883
Wed Sep 19, 2018 10:25 am
Forum: This is SolarChat !!
Topic: H-alpha images of September
Replies: 7
Views: 106

Re: H-alpha images of September

Thanks Stu, there were few days of high activity at the limb, I missed the 13th that was the most spectacular. No chance of imaging anything at the moment with the weather and work. Here the weather is sunny since too many weeks, we are experiencing an unusually hot September and tiger mosquitos are...
by krakatoa1883
Tue Sep 18, 2018 7:34 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 17
Views: 290

Re: Experimenting calcium imaging with small refractors

Thanks Mark, the link is very informative. Looking at the TOA a Strehl ratio close to 0.9 in the blue means that the scope can still be diffraction limited in the violet and near UV, really a terrific performer. I forgot to mention that in my tests I used a barlow or powermate in front of the Quark ...
by krakatoa1883
Tue Sep 18, 2018 1:45 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 17
Views: 290

Re: Experimenting calcium imaging with small refractors

Calcium imaging is indeed a challenging task for every refractor, however stopping down the aperture seems a good cure for both apos and achros. Navigating into Christian's web site I understand that he uses his TOA 150 at full aperture, if so it should be one of the best corrected instrument existi...
by krakatoa1883
Tue Sep 18, 2018 1:08 pm
Forum: This is SolarChat !!
Topic: H-alpha images of September
Replies: 7
Views: 106

Re: H-alpha images of September

Thanks Alexandra and Franco, prominences are not my specialty and I always find difficult to image them, your appreciation makes me really happy :D
by krakatoa1883
Tue Sep 18, 2018 9:18 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 17
Views: 290

Experimenting calcium imaging with small refractors

Last Sunday and Monday I spent some time in trying to understand which one of my small 80mm refractors performs better in calcium light. Made it just for fun :D but hope it may be useful for other imagers too. Worst of the group was a TS 80ED, a doublet with an element in FPL-51 glass ts80.jpg At fu...
by krakatoa1883
Tue Sep 18, 2018 8:53 am
Forum: This is SolarChat !!
Topic: H-alpha images of September
Replies: 7
Views: 106

H-alpha images of September

Not much details to image on the disc this month however in the past weeks some beautiful prominences were visible on the limb. I imaged some of the them with my Lunt-mod. refractor, these are from the 9th 2018-09-09-1340-RB-Halpha-proms.jpg day 10th 2018-09-10-0758-RB-Halpha-proms.jpg day 11th, qui...
by krakatoa1883
Mon Sep 17, 2018 4:42 pm
Forum: This is SolarChat !!
Topic: Surface contrast in CaK for various filter bandpasses.
Replies: 18
Views: 400

Re: Surface contrast in CaK for various filter bandpasses.

Very interesting and informative discussion. I have been able to image some large and unusually dark filaments through a Quark calcium device, which is declared to have a BP around 5A, a quite large one. It occurred only twice since I purchased it a year and a half ago. Hope to be able to find those...
by krakatoa1883
Mon Sep 17, 2018 3:20 pm
Forum: This is SolarChat !!
Topic: Chromosphere September 16th
Replies: 9
Views: 169

Re: Chromosphere September 16th

Very detailed images, Franco, well done!
by krakatoa1883
Mon Sep 17, 2018 3:14 pm
Forum: This is SolarChat !!
Topic: A variety from Sept 16 (with Gates of H*ll image)
Replies: 7
Views: 129

Re: A variety from Sept 16 (with Gates of H*ll image)

Fantastic images, a perfect match with that gate.
by krakatoa1883
Fri Sep 14, 2018 5:37 pm
Forum: This is SolarChat !!
Topic: Today's SUN (20180914) | FD images + proms
Replies: 6
Views: 218

Re: Today's SUN (20180914) | FD images + proms

Nice images, Pedro, when several prominences are visible a black disc surrounded by them (something like a coronagraph effect) can be really spectacular.
by krakatoa1883
Fri Sep 14, 2018 5:34 pm
Forum: This is SolarChat !!
Topic: Ca-H full disc of Sept. 13th
Replies: 6
Views: 108

Re: Ca-H full disc of Sept. 13th

Thanks everyone.

I never used ImagesPlus, I'll try, thanks Peter for your suggestion.
by krakatoa1883
Fri Sep 14, 2018 10:02 am
Forum: This is SolarChat !!
Topic: Tiny AR12721 in H-alpha and CaK: Sept10
Replies: 7
Views: 169

Re: Tiny AR12721 in H-alpha and CaK: Sept10

Peter, your 115mm seems well corrected in Cak, good images in H alpha too.
by krakatoa1883
Fri Sep 14, 2018 9:59 am
Forum: This is SolarChat !!
Topic: Nice hedgerow today
Replies: 5
Views: 136

Re: Nice hedgerow today

Truly spectacular, something of it persisted this morning but it's not so beautiful.

Alexandra, everybody here would pay for some rain, can we make an exchange ? rain for sun ? :lol:
by krakatoa1883
Thu Sep 13, 2018 10:26 am
Forum: This is SolarChat !!
Topic: Today's SUN (20180912) | FD images
Replies: 7
Views: 113

Re: Today's SUN (20180912) | FD images

Nice imagen, Pedro, well done!
by krakatoa1883
Thu Sep 13, 2018 10:21 am
Forum: This is SolarChat !!
Topic: Ca-H full disc of Sept. 13th
Replies: 6
Views: 108

Ca-H full disc of Sept. 13th

Just a full disc today, there is little to see on the chromosphere and nothing on the photosphere apart some facular zones. I noticed some prominences in calcium light but sky is hazy today and images would be too noisy. I also add an image of AR12721 taken on Sept. 10th before the group lost all of...
by krakatoa1883
Thu Sep 13, 2018 10:11 am
Forum: This is SolarChat !!
Topic: Today's Proms & AR2722 in HA & CaK | Sep 12th 2018
Replies: 6
Views: 109

Re: Today's Proms & AR2722 in HA & CaK | Sep 12th 2018

Hi Marty, your CaK pictures are among the best I have ever seen, you've found an ideal setup :bow
by krakatoa1883
Wed Sep 12, 2018 5:16 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 4001

Re: Narrowest 393.37 ever by Apollo Lasky

Nice to see these results. How does it perform behind a ND 3.8 astrosolar foil or a Herschel wedge ? Thanks.
by krakatoa1883
Mon Sep 10, 2018 4:54 pm
Forum: This is SolarChat !!
Topic: Sol from the 9th of September 2018.
Replies: 9
Views: 183

Re: Sol from the 9th of September 2018.

Fantastic discs, Eric. CaK proms in your images are exceptionally well contrasted, the PST mod is a real winner. My proms through the Quark seem ghosts in comparison to yours.
by krakatoa1883
Sun Sep 09, 2018 4:39 pm
Forum: This is SolarChat !!
Topic: 8th September, sunpot on a spotless day
Replies: 10
Views: 167

Re: 8th September, sunpot on a spotless day

Good work, Robert, your images on Flickr are very nice.