Search found 489 matches

by Bob Yoesle
Wed Jan 23, 2019 2:07 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

Thanks Mark - I was lucky to be able to get these etalons when such quality was available and still relatively affordable. I should note that the above images were wavelet processed in RegiStax6, but had no additional post processing, and the their RG630 ERF's were replaced by a single Baader DERF f...
by Bob Yoesle
Tue Jan 22, 2019 11:36 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: What camera?
Replies: 12
Views: 130

Re: What camera?

... you can get this chip in ZWO, PGR and Basler versions, does it make any difference? Just an FYI, A couple of years ago I fried my Point Grey Chameleon's sensor when the Baader film filter I made intermittently partially blew off in the wind. Point Grey replaced the entire camera for a standard ...
by Bob Yoesle
Tue Jan 22, 2019 10:06 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

One thing I do notice is that depending on the processing I can "pull" the double edge out of almost any image... Hi Ken, For me it was a long learning curve to discover exactly what an on-band image should look like. I still have trouble at times, especially in the typical relatively poor seeing I...
by Bob Yoesle
Sat Jan 19, 2019 7:27 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

Hi Marty, Upon reflection and going back to some references, I believe there could be a couple of things going on with your images. The recent images are better with regard to the double limb, but it is still subtly revealing itself. According to Bray & Loughhead in The Solar Chromosphere (1974, pag...
by Bob Yoesle
Sat Jan 12, 2019 2:15 pm
Forum: This is SolarChat !!
Topic: Quantum 6 setup
Replies: 14
Views: 353

Re: Quantum 6 setup

Not until reading Bob Yoesle's writings about the dreaded double limb did I realize that it was undesirable and must be eliminated. Yes, it's true - apparently a cult of righteous Double Limb Slayers has developed and is dedicated to eliminating for all mankind the dreaded Double Limb! Double Limb ...
by Bob Yoesle
Thu Jan 10, 2019 6:16 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: ERF and UV filter with 152mm f8 refractor and Quark
Replies: 5
Views: 257

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

Some would say no, and that it's over-kill, but I would go full-aperture for the best IR reduction. Depending on the scope mechanicals, you could also consider an internal ERF such as a smaller ~ 100 mm or so Baader, BelOptik, or Lunt ERF placed within the OTA. I also would consider a 50 mm KG3 filt...
by Bob Yoesle
Tue Jan 08, 2019 11:27 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

These are a major improvement Marty! Very much closer to being on band I would say.
by Bob Yoesle
Thu Jan 03, 2019 2:50 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Solarscope SF 70 filter DS
Replies: 7
Views: 316

Re: Solarscope SF 70 filter DS

Very Nice - detailed and contrasty - especially for SS.
by Bob Yoesle
Thu Jan 03, 2019 2:02 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

Looks like you nailed it Mark! Your greyscale is perfect:

https://www.flickr.com/photos/brierleyh ... otostream/
by Bob Yoesle
Wed Jan 02, 2019 7:28 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

Hi Marty, "... and if that kills the double limb, I'd be happy with that for the time being until I can figure out something better that is affordable." What do you consider affordable?! "Better" H alpha performance (especially double stacked) and "affordable" is kind of working at odds with each ot...
by Bob Yoesle
Wed Jan 02, 2019 3:44 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

Very nice implementation George! After the Quark, you are over f/30 and don't need the lenses. RE: PST etalon. Remember, an air spaced etalon is a different beast than a solid spaced etalon, and suffers from the decreased refractive index of air compared to a solid spaced etalon, and field and instr...
by Bob Yoesle
Mon Dec 24, 2018 7:28 pm
Forum: Solar Scope Modifications
Topic: Calcium K blocking filter
Replies: 17
Views: 623

Re: Calcium K blocking filter

Hi George, If I were you, I'd just add the PST to the Lunt as described, and get a pre-filter attached to the front of the Lunt module for larger aperture use: https://www.edmundoptics.com/p/394nm-cwl-50mm-dia-hard-coated-od-4-10nm-bandpass-filter/19839/ or https://www.edmundoptics.com/p/390nm-cwl-5...
by Bob Yoesle
Mon Dec 24, 2018 3:28 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

I'm on 3G speeds with my air card (I live in the boonies), so even if I shaved it down, it would take a long time to upload some where. But I'd be willing to try something if you have any ideas on how to best shave it down without culling good data. HI Marty, Don't really have any suggestion other ...
by Bob Yoesle
Mon Dec 24, 2018 3:22 pm
Forum: Solar Scope Modifications
Topic: Calcium K blocking filter
Replies: 17
Views: 623

Re: Calcium K blocking filter

Hi George, I think the Baader B-CCD is an all dielectric reflection filter on a clear BK7 or similar substrate, not an absorption filter. My CaK system has and continues to evolve. And I have only done this for CaK imaging use. Many years ago I and a few others started with a Baader Blue CCD filter ...
by Bob Yoesle
Sun Dec 23, 2018 7:59 pm
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

Hi Marty, Much improved! Yeah, you still have a little double limb. Could be a PST etalon tuning issue. And to my eye still a little soft towards and at the limb - but still much better ;-) How big is the above double stack video file? Perhaps if you can uploaded it to Dropbox, I could download it a...
by Bob Yoesle
Sun Dec 23, 2018 7:34 am
Forum: Solar Scope Modifications
Topic: PST Etalon with a Quark, Log & Results
Replies: 82
Views: 1956

Re: PST Etalon with a Quark, Log & Results

I agree Mark. I use minimal gamma in my capture process, generally underexpose, and bring out almost everything in post-capture processing. Marty PM'd me about this possibly being a double limb issue, but it doesn't look like it to me. The last image looks pretty good at the center of the disc, but ...
by Bob Yoesle
Mon Dec 03, 2018 5:40 pm
Forum: Solar Scope Modifications
Topic: Dismantling and modification of a PST CaK
Replies: 29
Views: 2106

Re: Dismantling and modification of a PST CaK

"Painted the inside of the OTA with Berger Antireflexfarbe."

Unfortunately, can't be delivered to the States. Anyone know of a similar product available in North America?
by Bob Yoesle
Mon Dec 03, 2018 5:01 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Internal vs. external Etalon placement question.
Replies: 2
Views: 393

Re: Internal vs. external Etalon placement question.

Ditto to what Mark has said ;-) Here's a little more detail as to why: All etalons are sensitive to the angle of light passing through them, and theoretically perform best with only parallel light passing at a 90 degree angle ("normal") to the reflective elements. The Sun, being an extended object i...
by Bob Yoesle
Wed Nov 21, 2018 4:02 pm
Forum: Solar Scope Modifications
Topic: optical contact experiments? Anybody?
Replies: 4
Views: 484

Re: optical contact experiments? Anybody?

"If an airspaced etalon is just two pieces of partially reflective glass contacted between mica spacers..." Not quite Apollo! Polishing to lambda/100 flatness across 25 mm is not too difficult using relatively standard production techniques, achieving this over the full area of a larger filter becom...
by Bob Yoesle
Mon Nov 19, 2018 3:16 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Rust on either Lunt or Coronado
Replies: 7
Views: 529

As shown in Ken's pics, and as in the above Cloudy Nights link, the Lunt issue now appears to be "glass disease:" https://en.wikipedia.org/wiki/Glass_disease See the Stage 1 and Sage 2 descriptions. It is known the Lunt uses BG glass (verses an ITF), which is a simple soda lime glass. It seems the K...
by Bob Yoesle
Thu Nov 15, 2018 8:36 pm
Forum: This is SolarChat !!
Topic: Old Coronado BF30
Replies: 22
Views: 923

Re: Old Coronado BF30

Hi Bart, No doubt a killer deal, as the filter itself is probably worth 10 times the price advertised. I have 3 BF 30's and they all have different brightness levels. Sometimes darker is better... Your proposed ancillary filters should work well, as the DERF will block UV and near IR, the 35 nm H al...
by Bob Yoesle
Thu Nov 15, 2018 4:44 pm
Forum: This is SolarChat !!
Topic: Old Coronado BF30
Replies: 22
Views: 923

Re: Old Coronado BF30

I checked out this filter as well... The Isle of Man blocking filters were designed for an etalon with a higher finesse and narrower FSR than the later Coronado or Solar Scope etalons. As opposed to today's Coronado and Solar Scope BF's with about a 6-8 A FWHM, the one in question probably has a 2-3...
by Bob Yoesle
Mon Nov 12, 2018 12:48 pm
Forum: This is SolarChat !!
Topic: Mg II in UltraViolet
Replies: 31
Views: 1664

Re: Mg II in UltraViolet

" Here are the simulations for a re-spaced classic C8 :
http://astrosurf.com/viladrich/astro/in ... -Plate.htm "

Thanks so much for this Christian!
by Bob Yoesle
Mon Nov 12, 2018 12:41 pm
Forum: Solar Scope Modifications
Topic: Lunt CaK B1200 + PST #1 yellow
Replies: 6
Views: 573

Re: Lunt CaK B1200 + PST #1 yellow

Hi George, I don't know if you saw these, but here's my recent results using a $350 Chameleon CCD camera. I already knew from a few years ago that double stacking CaK filters provides a contrast improvement. Triple stacking CaK filters is useful for bringing out details near to the solar limb. The s...
by Bob Yoesle
Sat Nov 10, 2018 2:35 pm
Forum: This is SolarChat !!
Topic: Mg II in UltraViolet
Replies: 31
Views: 1664

Re: Mg II in UltraViolet

Without the optical prescriptions of the lens system, it is impossible to know. The respaced SCT corrector probably does a better job of coma reduction, while I believe a separate system would be required for chromatic spherical aberration correction at 393 nm. For CaK work, the PST filters will be ...