Search found 880 matches

by Bob Yoesle
Wed Sep 28, 2022 5:04 am
Forum: This is SolarChat !!
Topic: September 24 sun and large prom
Replies: 21
Views: 302

Re: September 24 sun and large prom

Really like the results with the LS40! Also appreciate the negative prom and positive disc image.
by Bob Yoesle
Wed Sep 28, 2022 4:55 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Review of 3 Coronado 90's
Replies: 8
Views: 288

Re: Review of 3 Coronado 90's

These are etalons which have a tuning with a central wavelength that requires excessive tilt and/or richview mechanical pressure tuning to be brought on band. This can produce uneven contrast across the solar disc. Almost every MEADE etalon I have viewed through requires significant tilting to come ...
by Bob Yoesle
Mon Sep 19, 2022 4:13 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Review of 3 Coronado 90's
Replies: 8
Views: 288

Re: Review of 3 Coronado 90's

The mica etalon filters are more dependent on the quality of the raw natural material the etalon is made from, it's homogeneity, purity, color, etc. - and then the "luck" of how well a particular mica slice is cleaved and the resultant smoothness of the cleaved surface, and the lack of wed...
by Bob Yoesle
Sun Sep 18, 2022 1:48 pm
Forum: This is SolarChat !!
Topic: Question on capture settings
Replies: 20
Views: 324

Re: Question on capture settings

My processing is very similar to Christian's, and in my own non-expert experience I have found no significant difference between 8 bit avi and 12 bit ser files and processing. Moreover, compared to most people it seems I generally under-expose my images so as to not blow out active region details, y...
by Bob Yoesle
Tue Sep 13, 2022 5:42 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Comparison of Sepctroheliograph, Sundancer2 and Cak Lunt module
Replies: 14
Views: 489

Re: Comparison of Sepctroheliograph, Sundancer2 and Cak Lunt module

Hi Doug,

I stand corrected - that's a spectacular full disc image and the best I now have seen.

Thanks for the link (it didn't come up in a google search), and I'm glad to hear the software processing is much improved. Looking forward to seeing how far you can take angular resolution...

Bob
by Bob Yoesle
Tue Sep 13, 2022 3:08 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Comparison of Sepctroheliograph, Sundancer2 and Cak Lunt module
Replies: 14
Views: 489

Re: Comparison of Sepctroheliograph, Sundancer2 and Cak Lunt module

I've seen this said before. Even though you're looking at one limited wavelength (halpha) you don't need multiple lens, wouldn't though the polish of lens make a difference? A lens with a higher strehl or RMS wave wouldn't give a sharper/crisper image? Not really. Polish is one thing (naturally - b...
by Bob Yoesle
Mon Sep 12, 2022 5:26 pm
Forum: Solar Scope Modifications
Topic: Designing a new etalon for halpha
Replies: 19
Views: 441

Re: Designing a new etalon for halpha

This has always intrigued me and I ask now, where can I see a 100% on band H-alpha image ? Hi Rainer, I was referring to a CWL (central wavelength) of the filter system being tuned to be on-band, and this is not the same thing as a 100% on-band image. A 100% on-band image would have no parasitic co...
by Bob Yoesle
Mon Sep 12, 2022 3:59 pm
Forum: Solar Scope Modifications
Topic: AP155 and LS80 DSII
Replies: 32
Views: 804

Re: AP155 and LS80 DSII

Hi George, I have found the same thing - 10+ mm shifts in the position of the collimator/etalon assembly do not produce much of a noticeable effect. That being said, I still leave mine at the theoretical optimum position with the coincident collimator and objective focal points. I would think in thi...
by Bob Yoesle
Mon Sep 12, 2022 1:54 pm
Forum: Solar Scope Modifications
Topic: Designing a new etalon for halpha
Replies: 19
Views: 441

Re: Designing a new etalon for halpha

The realities of commercial production of etalons for consumer-grade recreational solar astronomy etalons is what I believe the issue really is. I and a few others are or have been lucky enough to own some of the better commercial etalon examples with outstanding performance, but these were not chea...
by Bob Yoesle
Fri Sep 09, 2022 2:13 pm
Forum: This is SolarChat !!
Topic: NSO - Daniel K. Inouye Solar Telescope
Replies: 13
Views: 262

Re: NSO - Daniel K. Inouye Solar Telescope

Mix them and you would probably get a magenta-pink!
Yes indeed - that's what you observe during a total solar eclipse!
by Bob Yoesle
Fri Sep 09, 2022 1:47 pm
Forum: This is SolarChat !!
Topic: NSO - Daniel K. Inouye Solar Telescope
Replies: 13
Views: 262

Re: NSO - Daniel K. Inouye Solar Telescope

Awesome resolution, and I note underlying photosphere granulation below the Hb chromosphere.

I re-processed the NSF - NSO image to create the actual color of H Beta with RGB values: R 0 G 239 B 255

Hbeta1_blue-scaled sm.jpg
Hbeta1_blue-scaled sm.jpg (485.27 KiB) Viewed 136 times
Open in new tab and click for larger,

Compressed for posting.

Bob
by Bob Yoesle
Sun Sep 04, 2022 4:52 pm
Forum: Solar Astronomy Outreach Experiences, Ideas and Techniques
Topic: Solar Observing Workshop at Phoenix Challenger Space Center hosted by Kevin LeGore’s FOCUS Astronomy!
Replies: 1
Views: 596

Re: Solar Observing Workshop at Phoenix Challenger Space Center hosted by Kevin LeGore’s FOCUS Astronomy!

Weather prostpects in Phoenix look good:

Cloud Cover Categories in Phoenix.png
Cloud Cover Categories in Phoenix.png (55.47 KiB) Viewed 344 times
Average High and Low Temperature in Phoenix.png
Average High and Low Temperature in Phoenix.png (76.72 KiB) Viewed 344 times

Maps from WeatherSpark.com

Bob
by Bob Yoesle
Tue Aug 23, 2022 1:18 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: "Old" ls60tha vs ls40tha
Replies: 6
Views: 282

Re: "Old" ls60tha vs ls40tha

The 60 will most likely be more suitable for imaging if that is your ultimate goal. But Mark is right. There is enough variability in etalon production that without an actual visual evaluation it might be a difficult side-by-side choice. But overall the 60 would be the safer bet - and you can save u...
by Bob Yoesle
Tue Aug 16, 2022 5:37 pm
Forum: This is SolarChat !!
Topic: SOLAR CYCLE 25 UPDATE
Replies: 33
Views: 1058

Re: SOLAR CYCLE 25 UPDATE

Good news! NOAA has finally adjusted their Solar Cycle Progression page to open with the correct early start and + 10 average sunspot number prediction curve, not the invalid start and mean prediction curve: The forecast for the current solar cycle is given by the grey line. This represents the uppe...
by Bob Yoesle
Sat Aug 13, 2022 2:41 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: CaK, Lunt or Daystar?
Replies: 10
Views: 284

Re: CaK, Lunt or Daystar?

The size is related to your focal length. The longer the FL, the larger the filter you should get. The module numerical value roughly translates to the max FL you can get a fill-disc un-vignetted image.
by Bob Yoesle
Sat Aug 13, 2022 4:55 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Scopes threaded for Solarmax 90
Replies: 2
Views: 159

Re: Scopes threaded for Solarmax 90

The older SM90s fit the TV101/102 scopes, and most of the Synta 100ED f9 OEM scopes (Skywatcher, Celestron, Orion...) Not sure the newer SM90 II or III threads are the same...
by Bob Yoesle
Sat Aug 13, 2022 4:51 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: CaK, Lunt or Daystar?
Replies: 10
Views: 284

Re: CaK, Lunt or Daystar?

Lunt or Solar Spectrum would be my choices.
by Bob Yoesle
Sat Aug 13, 2022 4:49 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Solarmax 70 with problems
Replies: 7
Views: 272

Re: Solarmax 70 with problems

To see what the deteriorated ITF looks like google "Coronado blocking filter rust" and look at Images tab. It probably has some kind of thread lock. It's hard to say why this is done, but you'll have to decide if heat, chemicals, etc. will be used to release and how best to access the filt...
by Bob Yoesle
Fri Aug 12, 2022 2:54 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Solarmax 70 with problems
Replies: 7
Views: 272

Re: Solarmax 70 with problems

The blocking filter has two main components, the first one in the diagonal nosepiece is known as the ITF and can deteriorate rather quickly, and is the likely source of the problem. Loosening the BF nosepiece and/or filter retaining rings may require specialized tools and methods, but usually can be...
by Bob Yoesle
Tue Aug 02, 2022 3:19 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Spectroscopic analysis of a Lunt CaK filter
Replies: 16
Views: 468

Re: Spectroscopic analysis of a Lunt CaK filter

For comparison, I had Mark Wagner do an evaluation of one of my legacy PST yellow dichroic CaK blocking filters (also apparently hard coated like the Alluxa): CaK PST Filter.png Tilting also brings this filter on-band at its advertised nominal 2.2 A FWHM. The transmission is not as high as Christian...
by Bob Yoesle
Tue Aug 02, 2022 1:36 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Test of an Alluxa 1.0 A Ca filter with Sol'Ex spectro
Replies: 5
Views: 368

Re: Test of an Alluxa 1.0 A Ca filter with Sol'Ex spectro

Hi Leo,

I believe this was a special batch order. You could email Alluxa and see if there were any others from this run, or what it might take to get another batch processed...
by Bob Yoesle
Wed Jul 27, 2022 3:48 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Test of an Alluxa 1.0 A Ca filter with Sol'Ex spectro
Replies: 5
Views: 368

Re: Test of an Alluxa 1.0 A Ca filter with Sol'Ex spectro

This filter appears quite similar to the Coronado PST dichroic hard-coated CaK filters: CaK filters PST v Alluxa.jpg It is a bit darker overall yellow transmission, with a similar purplish tint at most angles. CaK Alluxa package.jpg I'm hoping to follow Christian's lead with using this filter with a...
by Bob Yoesle
Wed Jul 27, 2022 3:29 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Baader 889nm Methane Filter
Replies: 7
Views: 273

Re: Baader 889nm Methane Filter

I jumped on the G-band and TiO filter bandwagon, but in reality these have sat in their boxes after getting an initial use... All the detail I need is already covered by three primary filter bands: the narrow-band chromosphere with CaK @ 394 nm and H alpha @ 656 nm, and photosphere with a wide-band ...
by Bob Yoesle
Wed Jul 27, 2022 1:33 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Getting Setup- Missing some parts, seeking suggestions
Replies: 7
Views: 325

Re: Getting Setup- Missing some parts, seeking suggestions

Honestly, stating your interest is for using the telescope for "occasional solar" use and imaging indicates you're going down a rabbit hole from looking at "pretty pictures" and not really knowing what's involved. The fact you want to engage in imaging without any real observatio...
by Bob Yoesle
Tue Jul 19, 2022 7:40 pm
Forum: Sunlit Earth
Topic: Sunset After A Thunder Storm
Replies: 4
Views: 146

Re: Sunset After A Thunder Storm

Thanks Alexandra, glad you like them.