Search found 439 matches

by Bob Yoesle
Wed Sep 19, 2018 5:47 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Experimenting calcium imaging with small refractors
Replies: 17
Views: 234

Re: Experimenting calcium imaging with small refractors

Thank for posting your results Raf ;-) Great images Pedro! The only drawback of the TOA 150 is its the price and ... its aperture. I wish I have a TOA 200 ;-) Hi Christian, my thought is that this seems to be pointing perhaps to using a reflector telescope such that you already have with an appropri...
by Bob Yoesle
Wed Sep 19, 2018 5:30 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: Narrowest 393.37 ever by Apollo Lasky

Hi Apollo, Hoping to get out for another run for prominence imaging this coming Monday the 24th... hoping some prominences will cooperate !-) Hi Mark, Brilliant no - just results of being a bit obsessive compulsive ;-) As you know, one must reduce the variables as much as possible, and it's impossib...
by Bob Yoesle
Wed Sep 19, 2018 3:58 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: Narrowest 393.37 ever by Apollo Lasky

A little better seeing today, so here are my latest test images for the CT 393.37 (used in Skybender tilt unit) - ED100/900, FireCapture set at minimum gain (160), gamma 700, histogram max ~ 190 +/- 10. All used a Baader B CCD and KG3 sub-aperture ERF's. All are 30 sec. captures @ 18 fps, aligned an...
by Bob Yoesle
Fri Sep 14, 2018 10:30 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: Narrowest 393.37 ever by Apollo Lasky

Had another chance to try some imaging before the weather deteriorated. The imaging train consisted of a Orion ED100/900, Baader Blue CCD and KG3 for ERF duties, Baader K line used as a blocker, a ND 0.6 for image brightness control, and finally either the PST CaK or CT 393.37 0.1 filter. All images...
by Bob Yoesle
Fri Sep 14, 2018 9:39 pm
Forum: This is SolarChat !!
Topic: Surface contrast in CaK for various filter bandpasses.
Replies: 18
Views: 396

Re: Surface contrast in CaK for various filter bandpasses.

Hi Peter,

Thanks for this very informative and interesting information.

Not sure what it would take either, but so far at least no one has made such a filter...
by Bob Yoesle
Wed Sep 12, 2018 1:38 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: Narrowest 393.37 ever by Apollo Lasky

Unfortunately I can no longer rely on Bob Yoesle to correctly use this filter if he is not going to install it in the Skybender. I plan to do just that in the coming week or so. I will have the Baader Blue CCD filter, KG3, Badder K line, followed by the CT393.34 0.1 correctly oriented in my Skybend...
by Bob Yoesle
Wed Sep 05, 2018 1:24 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

Hi Mark, I used a Baader Blue CCD filter, followed by a KG3, and then the Baader K line as ERF and blocking filters prior to the CT and PST filters. I will next attempt some tests with tilting the CT, and at f25 using a UO Klee barlow if/when my seeing allows. I likely will remove the Baader K line ...
by Bob Yoesle
Tue Sep 04, 2018 9:54 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

Hi everyone, I have a couple of new images from my first run that for some reason didn't process correctly the first time, but had better seeing/resolution. The overall results do not change however: CT 0.1 nm, exposure 0.100 ms: CT 0.1.jpg PST 0.2 nm, exposure 0.191 ms: PST 01.jpg There seems to be...
by Bob Yoesle
Mon Sep 03, 2018 4:30 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

Hi Mark, the CT filter was just behind the Baader K line - probably not ideal ;-) But I don't think it would have performed much differently without the reflection. Outside the reflected area still suffers compared to the PST double stack. Hi Stu, I will be attempting a lot more with the filter prio...
by Bob Yoesle
Mon Sep 03, 2018 3:45 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

That is my suspicion as well. The Badder K line has one flat component and one tilted. I'm working on tilt wedges of 2 and 4 degrees, and better spacing...
by Bob Yoesle
Mon Sep 03, 2018 1:43 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

My first results with the CT393.37pb0.1 are disappointing. However, a caveat is that I did not tilt any of the filters, and spurious reflections are apparent in my old system, and even more so with the Chroma Tech filter. I will therefore have to reserve a final judgement until I can do some additio...
by Bob Yoesle
Sat Sep 01, 2018 10:17 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

Hi Mark, I'm assuming the same limitations r/t collimator vs. telecentrics apply to the very narrow CaK filter as they to to H alpha. Since the filter uses a high index spacer construction, I assume this would result in better field angle performance for a collimator system compared to an air-spaced...
by Bob Yoesle
Fri Aug 31, 2018 10:00 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

Hi Mark, I checked with Dick at Chroma, and he confirmed the CT393.37bp0.1 is a single cavity and high index filter design. As Mark has pointed out, a larger f ratio is better than a shorter, and Dick also mentioned use in a collimator type system. I think Apollo deserves credit for passionately pur...
by Bob Yoesle
Thu Aug 30, 2018 2:22 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

If anybody knows a crew to manufacture some 150mm objectives to be .98 strehl for this filter as a primary dedicated scope , now is the time to step up out of the shadows and help please! Mike Jones has designed some nice scopes @ f8 and f10 3 years ago: https://www.cloudynights.com/topic/514152-hi...
by Bob Yoesle
Wed Aug 29, 2018 7:50 pm
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

FYI, I calculated from the data supplied a FWHM of 0.12 nm, a 10% transmission width of 0.42 nm, and a 1% transmission width or 1.41 nm. These figures approximate well with a single stack Lorentzian profile which states 10% ~ 3 x FWHM, and 1% ~ 10 x FWHM.
by Bob Yoesle
Wed Aug 29, 2018 8:02 am
Forum: Solar Scope Modifications
Topic: Narrowest 393.37 ever by Apollo Lasky
Replies: 152
Views: 3928

Re: 393.4 bp0.1 - yes it does exist.

Thanks for posting this SkyBurner. PB 0.1nm is not enough characteristic. How the sides are steep? What the skirt width? (VD) The filter is spec at 393.37nm but is better at 393.44nm which is better for K-line. The way the transmission data looks , there was a error in the run. I would say the block...
by Bob Yoesle
Wed Aug 22, 2018 1:42 am
Forum: Solar Scope Modifications
Topic: How to double stack a Lunt CaK Module? And ERF?
Replies: 22
Views: 624

Re: How to double stack a Lunt CaK Module? And ERF?

I'd be quite happy with a 2" baader blue CCD filter and a 2" KG3 filter at this point, as it would handle the thermal load for most applications in my largest refractor (6 inch). I suppose a hershcel wedge would do the same thing for the most part though honestly. To the best of my knowledge, the C...
by Bob Yoesle
Tue Aug 21, 2018 8:47 pm
Forum: Solar Scope Modifications
Topic: How to double stack a Lunt CaK Module? And ERF?
Replies: 22
Views: 624

Re: How to double stack a Lunt CaK Module? And ERF?

Not a good idea to have anything solar tightly secured, slightly loose is preferable. Nothing is a simple to do project in solar filters. REPEAT AFTER ME - NOTHING WILL BE SIMPLE . You won't find a 50 mm filter holder fitting these filters to standard 2 inch astronomy filter holders. You'd have to h...
by Bob Yoesle
Tue Aug 21, 2018 5:44 pm
Forum: Solar Scope Modifications
Topic: How to double stack a Lunt CaK Module? And ERF?
Replies: 22
Views: 624

Re: How to double stack a Lunt CaK Module? And ERF?

KG 3 v. KG 5 is a balancing act. KG3 has slightly better transmission for DSing both CaK and Ha, and slightly higher far IR blocking. For the long IR KG3 is about OD4, while KG 5 is OD5 - not sure this matters that much, and I am preferring the higher transmission. Others might feel differently, but...
by Bob Yoesle
Tue Aug 21, 2018 3:57 pm
Forum: Solar Scope Modifications
Topic: How to double stack a Lunt CaK Module? And ERF?
Replies: 22
Views: 624

Re: How to double stack a Lunt CaK Module? And ERF?

I don't suppose you know of a resource, like a picture even, of how to stack the eyepiece holder into the intact module? You can ditch the Skybender and just put the second Lunt CaK filter in a 1.25 " filter holder, and put that on your camera's C mount adapter. A couple of things - your optical sy...
by Bob Yoesle
Tue Aug 21, 2018 3:30 pm
Forum: Commercial Solar Filters/Cameras/Hardware
Topic: Different Ca-K options, differences?
Replies: 57
Views: 5097

Re: Different Ca-K options, differences?

See related post How to DS CaK
by Bob Yoesle
Mon Aug 20, 2018 6:36 pm
Forum: Solar Scope Modifications
Topic: Details of a telecentric lens for C8 Edge and Daystar filter
Replies: 6
Views: 587

Re: Details of a telecentric lens for C8 Edge and Daystar filter

HI Peter, Thanks for your excellent work on this :-) I have a favor to ask you - any chance you could work up a similar corrector for the original (non-HD) C8? I'm also considering modifying an original (non-HD) C8 with a re-spaced corrector ( https://www.cloudynights.com/topic/441781-respaced-corre...
by Bob Yoesle
Wed May 23, 2018 1:44 pm
Forum: Solar Scope Modifications
Topic: PST CaK mod
Replies: 22
Views: 1758

Re: PST CaK mod

Yes, it did have that (deteriorated) shinny gold filter as well, which shows as a blue substrate and ITF-like deterioration from the edge inward when held just right: Rusted CaK filter.jpg No 2 PST CaK filter.jpg My convention for the filter names is that the 1st filter after the objective is called...
by Bob Yoesle
Wed May 23, 2018 1:27 pm
Forum: This is SolarChat !!
Topic: Replacing the Rusted BF30 Filter
Replies: 54
Views: 2388

Re: Replacing the Rusted BF30 Filter

Thank you very much Mark for your input and expertise ;-)
by Bob Yoesle
Wed May 23, 2018 1:08 pm
Forum: This is SolarChat !!
Topic: Thermal Acclimation of My Lunt50
Replies: 33
Views: 1862

Re: Thermal Acclimation of My Lunt50

Looks to have great contrast when stabilized Mark. excellent imaging BTW!