Search found 525 matches

by Bob Yoesle
Mon Apr 15, 2019 1:19 am
Forum: This is SolarChat !!
Topic: When I win the lottery
Replies: 18
Views: 326

Re: When I win the lottery

Here's the skinny from Lunt: https://mailchi.mp/luntsolarsystems/join-us-at-neaf-and-double-stack-your-savings-save-10-off-gift-cards-starting-now-2205613?e=657ad57360 Intriguing for the ability to do "full disc" imaging - which indeed would require very large etalons to keep the Jacquinot spot larg...
by Bob Yoesle
Mon Apr 15, 2019 12:57 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: First solar shot ASI290
Replies: 7
Views: 100

Re: First solar shot ASI290

Looks great George!
by Bob Yoesle
Sun Apr 14, 2019 7:22 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Help tweak this PST + SM40II Double Stack?
Replies: 20
Views: 183

Re: Help tweak this PST + SM40II Double Stack?

Marty, I would be very careful about compression Richview tuning. 1) The DS etslons sometimes are farther to the red wing, and may require more compression to come on-hand with no tilt. 2) Going to the blue wing could apply too much pressure, stressing or fracturing the ERF (there are no collimating...
by Bob Yoesle
Sun Apr 14, 2019 3:20 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Help tweak this PST + SM40II Double Stack?
Replies: 20
Views: 183

Re: Help tweak this PST + SM40II Double Stack?

I would try the SM40 on its own on another small refractor. Leave the tilt alone (e.g. no tilt) and use the Richview only (compression - tightening) to tune the etalon. Add the etalon to the pre-tuned PST, and tilt the etalon just enough to get the reflections of the disc far enough to get the full ...
by Bob Yoesle
Sat Apr 13, 2019 1:11 am
Forum: Solar Scope Modifications
Topic: Tilt needed on a front ERF?
Replies: 2
Views: 133

Re: Tilt needed on a front ERF?

I recall the general parameter for both external and internal filter tilts is about 2 degrees.
by Bob Yoesle
Sat Apr 06, 2019 9:14 pm
Forum: Solar Scope Modifications
Topic: Crazy Idea...?
Replies: 4
Views: 190

Re: Crazy Idea...?

Removed.
by Bob Yoesle
Sat Apr 06, 2019 3:04 pm
Forum: Solar Scope Modifications
Topic: Crazy Idea...?
Replies: 4
Views: 190

Crazy Idea...?

Removed.
by Bob Yoesle
Sat Apr 06, 2019 2:02 pm
Forum: This is SolarChat !!
Topic: When I win the lottery
Replies: 18
Views: 326

Re: When I win the lottery

I think the price tag will be scary when it is released too.
A poster on CN stated it was "six figures," and this might be true given the cost of the LS230 (DS).
by Bob Yoesle
Wed Apr 03, 2019 10:43 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 39
Views: 2802

Re: Experimenting calcium imaging with small refractors

I have not measured it or taken one of the objective out of it's cell. The value is based solely on Mike Jones penciling it out theoretically. That said, a general rule for Achromats may apply for the curves and spacings being scalable to a percentage of the focal length, and therefore if the actual...
by Bob Yoesle
Wed Apr 03, 2019 12:21 am
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 39
Views: 2802

Re: Experimenting calcium imaging with small refractors

When increasing the lens spacing is there any negative effect on other wavelengths? Increasing spacing works for achromats too but improving blue-violet correction has an adverse effect on H alpha. Raf is correct, but it might not be as bad as it sounds. I think the acid test is needed in the form ...
by Bob Yoesle
Sat Mar 30, 2019 4:20 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 39
Views: 2802

Re: Experimenting calcium imaging with small refractors

Hi everyone, It seems in general that f-ratio for f-ratio, achromatic refractors have better longitudinal chromatic aberration control, while APO's have better lateral chromatic aberration. However, even my lowly Synta ED100/900 semi-APO doublet does well at CaK, which is one of the most difficult w...
by Bob Yoesle
Sun Mar 24, 2019 1:09 am
Forum: This is SolarChat !!
Topic: Latest Cycle 25 Prediction
Replies: 6
Views: 125

Re: Latest Cycle 25 Prediction

Hi everyone: indeed this is both potentially good news and very interesting science. And here's another piece of independent supportive data: "The development of the solar polar field strength throughout a solar sunspot cycle can be used to predict the magnitude of the next cycle and the peak of the...
by Bob Yoesle
Sat Mar 23, 2019 2:21 am
Forum: This is SolarChat !!
Topic: Latest Cycle 25 Prediction
Replies: 6
Views: 125

Latest Cycle 25 Prediction

This past December 6, 2018, the Center of Excellence in Space Sciences India (CESSI) reported that two of its scientists have made a prediction for the upcoming sunspot cycle. Solar physicist Dibyendu Nandi and his PhD student Prantika Bhowmik devised a new prediction technique, which simulates cond...
by Bob Yoesle
Thu Mar 14, 2019 11:11 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Help me decide on solar setup
Replies: 8
Views: 737

Re: Help me decide on solar setup

For narrow-band imaging (e.g. H alpha and CaK), the 102 f10 achromat will be superior to a shorter focal ratio ED refractor telescope due to generally better spherochromatic aberration performance. For white light continuum viewing/imaging, the chromatic aberration will not be too obtrusive, and can...
by Bob Yoesle
Sun Feb 24, 2019 8:29 pm
Forum: This is SolarChat !!
Topic: Saturday Sunshine - 23rd February
Replies: 15
Views: 333

Re: Saturday Sunshine - 23rd February

Hi Mark,

The DS w Quark/SM90 is amazingly good!

I'm also envious you have such good weather. We're not going to get much above freezing for another two to three weeks...

Driveway snow.jpg
Driveway snow.jpg (281.88 KiB) Viewed 259 times
by Bob Yoesle
Sun Feb 24, 2019 8:21 pm
Forum: This is SolarChat !!
Topic: CaK, 24022019, second try telecentric beam
Replies: 12
Views: 357

Re: CaK, 24022019, second try telecentric beam

Hi Bart,

Right now (when the sun comes out), I'll be using my Chameleon w 3.75 um pixels... may get something different in the future.
by Bob Yoesle
Sun Feb 24, 2019 8:17 pm
Forum: This is SolarChat !!
Topic: Weekend of fun in the sun with lots of new equipment
Replies: 16
Views: 434

Re: Weekend of fun in the sun with lots of new equipment

Very nice images Alexandra, especially H alpha!

I think we need to get Valery or Baader to address making a CaK spherical aberration corrector for the SCT, and the results will be even better!
SCT perfromance.jpg
SCT perfromance.jpg (179.89 KiB) Viewed 419 times
by Bob Yoesle
Sun Feb 24, 2019 7:41 pm
Forum: This is SolarChat !!
Topic: CaK, 23022019. Double plus triple.
Replies: 7
Views: 266

Re: CaK, 23022019. Double plus triple.

HI Bart,

Your results look similar to mine, and I can definitely see more detail at the limb with the triple stack.
by Bob Yoesle
Sun Feb 24, 2019 7:18 pm
Forum: This is SolarChat !!
Topic: CaK, 24022019, second try telecentric beam
Replies: 12
Views: 357

Re: CaK, 24022019, second try telecentric beam

Hi Bart - looks great! I'm anxious to press my TZ3/0.4 reducer into action when the Sun appears in a few months... Baader does specify the the focus will shift 5 mm for CaK with the TZ3: " Because they are made for H-apha-filters, they are designed for 656.3 nm (the red H-alpha-light); only the TZ3 ...
by Bob Yoesle
Sun Feb 24, 2019 6:53 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: New PST ITF?
Replies: 33
Views: 3921

Re: New PST ITF?

Hi M, I would not be too disregarding and suspicious - I doubt there are astronomy "cartels" trying to push more than you need when it comes to solar filters and safety. Indeed, my experience has been that the filter makers and suppliers have at times overestimated the blocking ability of their filt...
by Bob Yoesle
Tue Feb 19, 2019 9:53 pm
Forum: This is SolarChat !!
Topic: Our dear Richard Bailey
Replies: 12
Views: 391

Re: Our dear Richard Bailey

“We are like butterflies who flutter for a day and think it is forever.”
― Carl Sagan, Cosmos

After a long day in the warmth of the sun, we come home to rest at night in the cool of the earth.

Rest in peace Richard...

Sunset.jpg
Sunset.jpg (62.98 KiB) Viewed 371 times
by Bob Yoesle
Sun Feb 17, 2019 11:20 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: ERF and UV filter with 152mm f8 refractor and Quark
Replies: 7
Views: 730

Re: ERF and UV filter with 152mm f8 refractor and Quark

At 150 mm you really do need something beyond the 2 inch UV/IR type of filter... Go with Valery's Tri-band filter for the most versatility. If you only want H alpha, the Baader DERF would work as well. Avoid the simple red or yellow glass absorptive objective ERF's. See this recent Cloudy Nights pos...
by Bob Yoesle
Sun Feb 17, 2019 10:03 pm
Forum: This is SolarChat !!
Topic: CaK, 16022019. SolarMonitor plus experiments
Replies: 17
Views: 447

Re: CaK, 16022019. SolarMonitor plus experiments

Thanks Bart, nice to see in the comparisons!
by Bob Yoesle
Sun Feb 17, 2019 9:59 pm
Forum: Solar Scope Modifications
Topic: Beloptik ha system
Replies: 3
Views: 299

Re: Beloptik ha system

"Personally, no. Lots of people on here have tried the telecentric / air spaced etalon route and it yields results with too wide a bandpass." I would expect that, since 0.7 angstrom air spaced etaons were originally intended for use on the front objective, where the 0.25 degree field angle of the Su...
by Bob Yoesle
Sun Feb 17, 2019 4:08 pm
Forum: This is SolarChat !!
Topic: CaK, 16022019. SolarMonitor plus experiments
Replies: 17
Views: 447

Re: CaK, 16022019. SolarMonitor plus experiments

Thanks for the trials you gone through Bart! Could you post or PM me the image trials of the filter combinations? Just curious to see all the results for the comparison...