Search found 994 matches

by Bob Yoesle
Sat Mar 16, 2024 5:18 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Solar equipment big plan
Replies: 1
Views: 173

Re: Solar equipment big plan

There are no guarantees or assurances that even with the best equipment you won't have issues or "have to look back." Sorry, them's the facts, and I speak from experience, not hypotheticals. You should start out smaller and easier before going to larger and more complex. You don't start ou...
by Bob Yoesle
Mon Mar 11, 2024 5:58 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Double-stack LS80 with Coronado SM90?
Replies: 3
Views: 140

Re: Double-stack LS80 with Coronado SM90?

It all depends on the CWL of the front etalon and how much tilt it needs to get on-band, regardless of who makes it. Too high a CWL will mean more tilt is needed, which can possibly introduce banding or a contrast gradient. No way to really tell until you get it, unless the party selling it can test...
by Bob Yoesle
Thu Mar 07, 2024 12:55 am
Forum: Solar Scope Modifications
Topic: Coronado CaK 70 with Lunt BF
Replies: 17
Views: 562

Re: Coronado CaK 70 with Lunt BF

That's a really nice image, and because the main blocker is in a collimated lens system, it's likely a bit tighter in bandpass than the PST CaK version. The MS70 CaK objective side blocker-ERF should be intact, but I'm not sure of it's characteristics. I doubt it blocks anything beyond about 1200-14...
by Bob Yoesle
Tue Mar 05, 2024 7:47 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Filter Tilt mount available soon from RAF camera
Replies: 21
Views: 1158

Re: Filter Tilt mount available soon from RAF camera

Looks very impressive Mark, looking forward to your results.
by Bob Yoesle
Sat Mar 02, 2024 3:04 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Understanding Lunt Blocking Filters
Replies: 2
Views: 319

Re: Understanding Lunt Blocking Filters

Correct, your detail is strictly limited by the resolving power of the objective and the seeing. A larger straight through blocking filter would be my choice. It will provide less centering issues for the sweet spot when viewing/imaging, and hopefully allow for an un-vignetted view should you use a ...
by Bob Yoesle
Tue Feb 27, 2024 12:44 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: New CaK etalons from Solar Spectrum
Replies: 22
Views: 1512

Re: New CaK etalons from Solar Spectrum

I know Mark had some production issues with a coating machine needing parts and the like. And he refused to turn out products that ultimately would end up coming right back. Sometimes you just have to bite the bullet and wait - try an Astro-Physics refractor for example, where the wait time is also ...
by Bob Yoesle
Fri Feb 23, 2024 1:19 pm
Forum: Solar Scope Modifications
Topic: Coronado CaK 70 with Lunt BF
Replies: 17
Views: 562

Re: Coronado CaK 70 with Lunt BF

Hi Jonny,

The focuser and adapter came with the telescope when I bought it, so I assume it came from Starlight Instruments.

The electronics is a TEC cooler I built many years ago for my PGR Chameleon.

Bob
by Bob Yoesle
Thu Feb 22, 2024 3:25 pm
Forum: Forum Support Issues
Topic: Where is my topic gone?
Replies: 6
Views: 580

Re: Where is my topic gone?

If you PM me I can tell you very likely why.
by Bob Yoesle
Thu Feb 22, 2024 2:26 pm
Forum: Solar Scope Modifications
Topic: Coronado CaK 70 with Lunt BF
Replies: 17
Views: 562

Re: Coronado CaK 70 with Lunt BF

Although I haven't used one, in addition to the above filters mentioned by Mark, Maier Photonics makes a relatively inexpensive 393 bandpass filter that some have used successfully.
by Bob Yoesle
Sat Feb 03, 2024 2:50 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Barlow with Lunt CaK
Replies: 9
Views: 489

Re: Barlow with Lunt CaK

My choice for optimum high resolution work would be to use a telecentric configuration and the Baader Research Grade TZ3 , which is stated specifically corrected for CaK "Diffraction limited design with about 80% Strehl also at 396 nm (CaK)." Both the new TZ-3S and TZ-4S are stated to be &...
by Bob Yoesle
Sat Jan 06, 2024 2:34 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: New CaK etalons from Solar Spectrum
Replies: 22
Views: 1512

Re: New CaK etalons from Solar Spectrum

I wonder what is the peak transmission of these filters. Do you have any data on this ? Hi Christian, Per Mark: "The ones we checked went from 15% to 5% . This was caused by the difference in shade of the mica. With all mica, the darker it is the lower T and broader Hw with the same coating de...
by Bob Yoesle
Thu Jan 04, 2024 6:58 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: New CaK etalons from Solar Spectrum
Replies: 22
Views: 1512

Re: New CaK etalons from Solar Spectrum

Hi Dennis, I'm confused by the statement "hopefully the design is done in mind for 100% imaging." Do you mean as opposed to visual? Camera sensors are generally much more sensitive than retinas with yellowed eyeball lenses, so that would seem to imply you want less throughput for the block...
by Bob Yoesle
Wed Jan 03, 2024 9:23 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: New CaK etalons from Solar Spectrum
Replies: 22
Views: 1512

Re: New CaK etalons from Solar Spectrum

Hi Christian, I'll have to make an inquiry with Mark, not sure he has a cleaved piece of mica yet. It will be an ~ 0.5 A RG18 etalon in a Housing I have left over from a previous 2 A DayStar CaK T Scanner (and possibly heated if not TEC controlled). It has hard coated blockers from Alluxa. I'll post...
by Bob Yoesle
Wed Jan 03, 2024 3:34 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: New CaK etalons from Solar Spectrum
Replies: 22
Views: 1512

New CaK etalons from Solar Spectrum

It's now official. Solar Spectrum has announced the availability of CaK etalon filter systems with FWHM's less than 1 Angstrom. K Line Solar Spectrum SM.png Solar Spectrum. Due to the limitations of even the most modern interference filter hard-layer depositing, reliable CWL uniformity and bandpass...
by Bob Yoesle
Mon Jan 01, 2024 2:09 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: New Years's Eve Flare
Replies: 3
Views: 291

Re: New Years's Eve Flare

Great capture! An X5, strongest yet for SC25.
by Bob Yoesle
Fri Dec 22, 2023 2:12 pm
Forum: Solar Scope Modifications
Topic: A Filter Journey
Replies: 27
Views: 7072

Re: A Filter Journey

You're welcome Mark - I just recently became aware of these myself ;-)
by Bob Yoesle
Thu Dec 21, 2023 1:50 pm
Forum: Solar Scope Modifications
Topic: A Filter Journey
Replies: 27
Views: 7072

Re: A Filter Journey

@Bob, are you saying that I can replace the regular ITF in the BF30 with the KG3/IR-UV cut ITF replacement filter and not have to do any other mods ?, the 2 etalons/filters have not been modified/changed in anyway.. Yes, since you are leaving the RG630 ERF's on the etalon(s) which are part of the r...
by Bob Yoesle
Tue Dec 19, 2023 7:19 pm
Forum: This is SolarChat !!
Topic: New Solar Prediction Update and Experimental Display
Replies: 10
Views: 916

New Solar Prediction Update and Experimental Display

NOAA' Space Weather Prediction Center has put forth an experimental - and IMHO much better - solar cycle forecast display. The prediction shows a mean sunspot peak of about 154 around May-June 2024, with a range from 134 - 177. cycle update v2.png This display gives a more accurate demonstration of ...
by Bob Yoesle
Mon Dec 11, 2023 3:38 pm
Forum: SPoD Archive
Topic: December Solarchat Zoom meeting! Dec 10th 1800GMT
Replies: 27
Views: 2363

Re: December Solarchat Zoom meeting! Dec 10th 1800GMT

Many thanks to George for the fantastic presentation. And thanks to Klaus for addressing my H alpha H beta inquiry - I'm retired, but have a lot of "irons in the fire" right now... Something for later next year perhaps - or I'll wait to see how your efforts turn out ;-)

Bob
by Bob Yoesle
Thu Nov 30, 2023 5:48 pm
Forum: Solar Scope Modifications
Topic: Blackest black paint?
Replies: 11
Views: 3202

Re: Blackest black paint?

I recently had the chance to try out Musou Black versus plain flat black spray paint on a shiny aluminum mirror cell back plate, and the Musou Black is definitely darker: Black anodization on the left, black spray paint on the right. Both appear to have about the same reflectivity: Anodizing vs blac...
by Bob Yoesle
Thu Nov 30, 2023 3:34 pm
Forum: This is SolarChat !!
Topic: CAK Imaging with Re-spaced C6R refractor - 30 Nov 23 (New Images Added)
Replies: 24
Views: 881

Re: CAK Imaging with Re-spaced C6R refractor - 30 Nov 23

Hello Alfred,

Looks good. What respace distance did you use? Did you stop down the aperture at all?

Bob
by Bob Yoesle
Sat Nov 18, 2023 6:56 pm
Forum: This is SolarChat !!
Topic: Clueless me regarding the "sweet spot" size
Replies: 1
Views: 217

Re: Clueless me regarding the "sweet spot" size

Any of the front 0.7 A etalon telescopes will have about a 1 degree Jacquinot spot. Double stacking these will reduce the spot to about 0.8 degree. A narrower etalon always has a smaller Jacquinot spot. For internal etalons, the above figures are reduced by the field angle magnification, which is th...
by Bob Yoesle
Sat Nov 11, 2023 2:04 pm
Forum: This is SolarChat !!
Topic: More playing with the new double stack
Replies: 18
Views: 1123

Re: More playing with the new double stack

Hi Peter, My 'ouch' comment was actually referring to yltansg having his etalon dropped. I think the original image processing of the limb image is what looked like you had a typical single stack double limb. In the last image, a double limb appears minimal, and otherwise the tuning looks good, but ...
by Bob Yoesle
Fri Nov 10, 2023 2:40 pm
Forum: This is SolarChat !!
Topic: More playing with the new double stack
Replies: 18
Views: 1123

Re: More playing with the new double stack

Ouch! I try to use visually every few weeks and retune if needed. Peter: Can you post the image at the limb that isn't the ubiquitous mixed negative disc/positive prom? I ask because this is typically used to hide the double limb of the photosphere apparent with single stacking, which should disappe...
by Bob Yoesle
Tue Nov 07, 2023 5:13 pm
Forum: Solar Radio, Magnetometry and Spectroscopy
Topic: Probably my last SHG image for 2023
Replies: 9
Views: 1966

Re: Probably my last SHG image for 2023

Hi Doug, Single stacked always seem to give a much more even full disk than double stacked. For the most part the disc evenness with double stacking etalons is highly dependent on the individual etalon parameters and quality. With good uniformity etalons needing minimal tilts to get on-band and remo...
by Bob Yoesle
Sat Oct 28, 2023 2:24 pm
Forum: This is SolarChat !!
Topic: Cycle 25 progression
Replies: 26
Views: 1809

Re: Cycle 25 progression

Hello Stu - love the data driven approach! NOAA has a new "experimental" prediction posted here . cycle_update.png Hathaway and Upton have revised their prediction as well. PredictSSN_23_24_25.jpg I wonder how the 'double peak' of this cycle will pan out compared to previous cycles. Mark I...
by Bob Yoesle
Fri Oct 27, 2023 3:30 pm
Forum: Solar Scope Modifications
Topic: Blackest black paint?
Replies: 11
Views: 3202

Re: Blackest black paint?

You're pretty much stuck with paints for small internal surfaces. Some people add carbon black to regular flat black paints. Spray paint fogging with standard flat black can work well; and if applied while paint is still tacky, blowing in a little carbon black (some use back printer toner) can also ...
by Bob Yoesle
Fri Oct 27, 2023 2:19 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Another Lunt etalon question???
Replies: 3
Views: 729

Re: Another Lunt etalon question???

1) A pressure-tuned internal DS for the 50 would usually use smaller collimating lens optics and another etalon, and might cost as much or more than a front etalon. Internal etalons suffer from more scattered light (more optical surfaces) and increased field angle magnification, reducing the size of...
by Bob Yoesle
Sun Oct 01, 2023 5:32 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: PST rust repair?
Replies: 4
Views: 1198

Re: PST rust repair?

you may find one of the many modders on here has a gold tube they are happy to sell - you could just swap the objective over then. A great idea! However, since you'd be replacing the rusted ITF coating on your OEM objective with likely a later un-ITF coated objective, you'll also have to get a stan...
by Bob Yoesle
Tue Sep 26, 2023 8:51 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Measurement of a DayStar PE 0.6 A
Replies: 23
Views: 3087

Re: Measurement of a DayStar PE 0.6 A

It's the same nonsense DayStar stated dismissing double stacking etalons.

It revealed either complete ignorance of etalon optical principles and the filter making industry, or was marketing propaganda for fooling the less well informed consumer.

It's buyer beware for either circumstance.
by Bob Yoesle
Mon Sep 25, 2023 3:31 pm
Forum: Solar Scope Modifications
Topic: Small Etalon Improvement For Only $15 USD (13 Euros)
Replies: 91
Views: 20282

Re: Small Etalon Improvement For Only $15 USD (13 Euros)

Indeed, the small amount of physical pressure needed to effect a gap spacing change is remarkable.
by Bob Yoesle
Mon Sep 25, 2023 3:23 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Measurement of a DayStar PE 0.6 A
Replies: 23
Views: 3087

Re: Measurement of a DayStar PE 0.6 A

My first H alpha filter was a 1976 DayStar 0.7 ATM, and it was superb. Mark Wagner (then at DayStar) replaced the failed blockers around the mid 90's. I really regret having sold it. If you check the DayStar website , you can see how they now leave a lot of wiggle room in their warranty. The SE (for...
by Bob Yoesle
Sat Sep 23, 2023 9:45 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: If CaK is best at F10 -
Replies: 59
Views: 5592

Re: If CaK is best at F10 -

I believe from reliable sources this is in the works.
by Bob Yoesle
Sat Sep 23, 2023 1:14 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: If CaK is best at F10 -
Replies: 59
Views: 5592

Re: If CaK is best at F10 -

So far the Alluxa 1.0 CaK filters appear overall to be the better of the two between the Chroma and Alluxa, with the chroma having less uniformity. And while the 2.2 PST CaK filters also appear very uniform, they have a wider overall bandpass in real world implementation. Double stacking with either...
by Bob Yoesle
Sat Sep 23, 2023 3:08 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: If CaK is best at F10 -
Replies: 59
Views: 5592

Re: If CaK is best at F10 -

Question to Christian et al; has the filter from a CaK PST or from a Lunt been scanned with the same resolution etc as the ALluxa 1a? Mark scanned my 2.2 A PST CaK filter and Chroma 1.0 A CaK here: CT v PST CaK filter curves.png Here's the Alluxa 1.0 A CaK filter (no tilt): Alluxa 393.37 1.0 M Wagn...
by Bob Yoesle
Mon Sep 18, 2023 3:38 pm
Forum: This is SolarChat !!
Topic: Ca K double-stack prom / filament / spots on Sept 7 with the TOA 150
Replies: 12
Views: 460

Re: Ca K double-stack prom / filament / spots on Sept 7 with the TOA 150

Awesome Christian, especially the limb prominence image!
by Bob Yoesle
Sun Sep 17, 2023 1:59 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Reducers for 393nm Wavelength?
Replies: 7
Views: 1156

Re: Reducers for 393nm Wavelength?

I asked Baader about using the RG 0.4 and 0.7 focal reducers intended to be used for the TZ3 focal reducers. They responded: "We actually haven't tried it out yet, as a reducer usually is not necessary for the CaK-filter (which operates at the native f/ratio of the tellescope), and the SolarSpe...
by Bob Yoesle
Mon Sep 11, 2023 5:54 pm
Forum: Solar Scope Modifications
Topic: Small Etalon Improvement For Only $15 USD (13 Euros)
Replies: 91
Views: 20282

Re: Small Etalon Improvement For Only $15 USD (13 Euros)

It looks like it might be AR coated. Once you remove the ERF cell and flip it you can reverse the ERF itself to maintain the OEM orientation. Has anyone tried it with PST etalon? See previous post in this thread. The PST is already similarly mechanically pressure tuned, but needs some additional sup...
by Bob Yoesle
Mon Sep 04, 2023 11:33 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: If CaK is best at F10 -
Replies: 59
Views: 5592

Re: If CaK is best at F10 -

There are actually two separate issues. Spherochromatism is telescope dependent - some perform very well like the Takahashi TOA 130 & 150 at only f7+. The Synta ED100/900 I have used also seems to perform quite well at f9 with single 2.2 A and double stacked CaK filters (1.4 A) - although I' sur...
by Bob Yoesle
Mon Sep 04, 2023 10:39 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Measurement of a - very bad - Quark Combo
Replies: 5
Views: 1060

Re: Measurement of a - very bad - Quark Combo

The bad one looks clearly like it's a double peak. I guess that means there are effectively two etalons in there (presumably due to some separation in the mica?). Mica is a birefringent crystal , and I wonder if it is possible that one or both of the polaroids are defective (or misaligned) and ther...
by Bob Yoesle
Sun Aug 20, 2023 11:33 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Technology of Skywatcher SolarQuest mount
Replies: 4
Views: 985

Re: Technology of Skywatcher SolarQuest mount

Found this video that attempts to explain fundamentals of how SolarQuest works. Anyone else got a detailed explanation? Hmmm... I find video succeeds in explaining the fundamentals of how the SolarQuest works quite well. Surprised that you don't find that video's explanation detailed enough. If you...
by Bob Yoesle
Sat Aug 19, 2023 5:16 pm
Forum: This is SolarChat !!
Topic: My woes with a Solar full disk in H-a 16.08.
Replies: 20
Views: 898

Re: My woes with a Solar full disk in H-a 16.08.

Setting up and tuning is quite difficult and I am not very satisfied with the results. FD still isn't the best, although longer focal length images don't look terrible. It'll be another birth before I tune it out. Hello Petr. The image processing by Stu is very good. But as Valery notes, it seems t...
by Bob Yoesle
Thu Aug 03, 2023 2:05 am
Forum: Solar Scope Modifications
Topic: Circular polarizer measurements and thoughts
Replies: 15
Views: 5069

Re: Circular polarizer measurements and thoughts

Hi Christian, Mark told me about a new CP that is available with high overall transmission: the Breakthrough X4 CPL . It doesn't look too good for 400 nm or less. But their sales page has a graph which shows the Zeiss T* POL CP having possibly a relatively good transmission below/near 400 nm: X4_CPL...
by Bob Yoesle
Sun Jul 09, 2023 2:35 am
Forum: Solar Scope Modifications
Topic: Small Etalon Improvement For Only $15 USD (13 Euros)
Replies: 91
Views: 20282

Re: Small Etalon Improvement For Only $15 USD (13 Euros)

If you're almost on-band with little tilt then there is really no reason to implement a compression tuning system for an external etalon use. It may also be unnecessary for double stacking with a telecentric arrangement at the focuser side of the optics. In ay event, very little compression is actua...
by Bob Yoesle
Sat Jun 24, 2023 1:47 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Got my RG-18 0.3 back!
Replies: 14
Views: 1577

Re: Got my RG-18 0.3 back!

As Mark stated, the double limb at 0.3 A and as seen in your images is minimal. I think I would be more than satisfied with that, rather than messing with the hassle and reduced image brightness of double stacking. But then again there's only one way to find out - try it and see how the pluses and m...
by Bob Yoesle
Fri Jun 23, 2023 2:22 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: DayStar Quantum - South England
Replies: 21
Views: 2231

Re: DayStar Quantum - South England

Noticed the Operating Temp is 97 F (36 C). 97 F is really low for a solid-spaced etalon unless you're in the arctic. The typical operating temp. should be 30 or more degrees F higher (~ 130 F or 55 C) - minimum. The serial number 080807 indicates the filter manufacture date is August 8, 2007 - so th...
by Bob Yoesle
Fri Jun 23, 2023 1:44 pm
Forum: Solar Scope Modifications
Topic: Small Etalon Improvement For Only $15 USD (13 Euros)
Replies: 91
Views: 20282

Re: Small Etalon Improvement For Only $15 USD (13 Euros)

Depends on how far off-band the native CWL is. A small amount of compression would likely be OK. If it needs a lot of compression, the etalon gap without central compression will get pretty uneven, and the etalon FWHM will widen considerably.

Bob
by Bob Yoesle
Tue Jun 20, 2023 5:43 pm
Forum: Solar Scope Modifications
Topic: Small Etalon Improvement For Only $15 USD (13 Euros)
Replies: 91
Views: 20282

Re: Small Etalon Improvement For Only $15 USD (13 Euros)

My preference it to loosen when not in use, as this will allow the foam ring to "relax" back to "normal" and relieve any stress on the silicone buttons that constrain the the edge of the etalon plates.
by Bob Yoesle
Tue Jun 06, 2023 10:12 pm
Forum: Solar Prominence/Filament Classification Project
Topic: Filaments in IR? or What? 5 | 25 | 23
Replies: 96
Views: 8200

Re: Filaments in IR? or What? 5 | 25 | 23

Hi James and Alexandra, Unfortunately, Aaron's methodology and equipment was not ideal and suspect for making such sweeping claims - a 70 mm telescope used at 850 nm has at best a resolution of 3 arcsec. I suggested setting up a topic in the experimental part of the forum, the 'prominence and filame...