Why bandwidth, why! (High Angstrom Fever)

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
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Valery
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Re: Why bandwidth, why! (High Angstrom Fever)

Post by Valery » Tue May 24, 2016 12:23 am

There is an easy way to go.
Just put enough cash and ask DayStar or Solar Spectrum to make a 0,2A filter for you.
This costs less than 7 years of life and permanent disappointment.
Last edited by Valery on Tue May 24, 2016 2:59 am, edited 1 time in total.
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by solarchat » Tue May 24, 2016 2:33 am

I get at least 5 emails a week from people asking about what they should buy in solar scopes. I always recommend a .5-.6A setup but almost invariably the person thinks they know a cheaper or better way to do something and they almost always opt for the cheaper solution first. Then they generally end up spending 2 or 3 times more money than what I recommend as they progress through diferent instruments.
If someone had told you these things, and maybe they did, you probably would have also ignored them in favor of a cheaper first scope. It’s just human nature in this hobby.
Stephen W. Ramsden
Atlanta, GA USA
Founder/Director Charlie Bates Solar Astronomy Project
http://www.solarastronomy.org

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by Montana » Tue May 24, 2016 7:03 am

I've always said that, once you have seen a double stack you can never go back!

However, I wouldn't say a 0.3A Daystar or Solar spectrum would suit me either as there is too wide a base and contrast is low. It has to be a DS front mounted etalon.

Alexandra

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by Merlin66 » Tue May 24, 2016 7:23 am

Or alternatively, a SHG set-up....
I believe one of the great strengths of the SHG is the ability to select not only the bandwidth but also accurately establish the central wavelength for on/ off band measurements.
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
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"Astronomical Spectroscopy for Amateurs" and
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Re: Why bandwidth, why! (High Angstrom Fever)

Post by solarchat » Tue May 24, 2016 10:38 am

Agreed with both of you. Although, I have recently added internal double stakcs to the 2 Lunt 100s that I use in outreach and they have really improved the performance of these at Lunt. I now use two triple stacked LS100s at al my events. :)

I beliuieve that the SHG is the future though and can’t wait for the technology to come along to a consumer usable out of the box setup.
Stephen W. Ramsden
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Founder/Director Charlie Bates Solar Astronomy Project
http://www.solarastronomy.org

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by Merlin66 » Tue May 24, 2016 10:58 am

Stephan,
In the new book "Imaging Sunlight", I show details and results from Fulvio Mete's prototype SolarScan Compact SHG.
It is hoped that this will be commercialized soon and add to the solar amateurs tool kit.
Exciting days!
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.yahoo.com/neo/groups/ast ... scopy/info
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by Montana » Tue May 24, 2016 11:12 am

That sounds interesting :)

Alexandra

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by Valery » Tue May 24, 2016 12:09 pm

Montana wrote:I've always said that, once you have seen a double stack you can never go back!

However, I wouldn't say a 0.3A Daystar or Solar spectrum would suit me either as there is too wide a base and contrast is low. It has to be a DS front mounted etalon.

Alexandra
Hi Alexandra,

I have experimented with a lot of SS and DS etalons of different bandwidth. And being based on this first hand experience, I would say that you are right only in the case of VISUAL works and only for disk details. However, in the case of imaging, a very good SS etalon offers BETTER performance in many if not in most cases. Especially if these etalons are air-spaced - like in PST telescopes. They are significantly more "bright" than some solid spaced etalons.
DS in the case of imaging, is the king is two cases: at the limb and in the case of fainter dark filaments.


Valery
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by Valery » Tue May 24, 2016 12:21 pm

Merlin66 wrote:Stephan,
In the new book "Imaging Sunlight", I show details and results from Fulvio Mete's prototype SolarScan Compact SHG.
It is hoped that this will be commercialized soon and add to the solar amateurs tool kit.
Exciting days!
Despite all the hopes, this techology will never offers such a performance as the schemes with FP etalons.
Spatial and time resolution will always be on the FP etalons side, as well as possibility to use lucky imaging technique.
In brief, I am pessimistic about SHGs.


Valery
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by rxdeath » Tue May 24, 2016 6:27 pm

so without inciting a riot, is that recommendation the 80ds as a best buy to as low as bandwidth as possible while being reasonable with price, say 5k range? i use lunt as an example because it's what i have experience with and prefer over other vendors. or get a solar scope ds unit to go with a lunt body? i am not a huge fan of the quarks, but i suppose that should be in there too.

i think the SHG project when brought to an equal stage of development (very cheap and small) could give a lot more people access to our hobby, so anything that does that is good, but agree it will take some serious innovation in order to surpass ha views from commerically available setups. but i'd rather have 10,000,000 people see an image that is a 6 rather than 1,000 see a perfect 10. jack-of-all-spectrums, master of none (for now?) is cool depending on your particular goals.

triple stack 100? my head just exploded. is there an easy reference to a picture of this setup in action, as well as an image comparing ds and (wow) ts?

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by Merlin66 » Tue May 24, 2016 6:55 pm

Only time will tell...
One aspect of the SHG which should not be overlooked is the ability to do scientific analysis of the solar magnetic fields and associated effects.
By accurately determining the observation wavelength we can also look more closely at off band phenomenon.
These areas of research are almost impossible with traditional amateur filters.
BTW a good hi-res SHG can be build for much less than a similar aperture F-P filter scope.
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.yahoo.com/neo/groups/ast ... scopy/info
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by Merlin66 » Tue May 24, 2016 7:01 pm

Valery,
Achieving good spatial resolution is easy with the SHG. I agree that the time resolution is an issue, but with the advent of fast frame (ROI) >600 fps cameras and utilizing a scanning mirror I think the technology can come close.
When you consider how far the digital SHG has come in the last few years and the ongoing development of processing software, I'm looking forward to the next generation of instruments and seeing the results of their improved potential.
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.yahoo.com/neo/groups/ast ... scopy/info
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by solarchat » Tue May 24, 2016 10:10 pm

rxdeath,

Any riots on this site will be immediately squashed by me, the forum admin. A little history; I started this forum after witnessing the incessant blowhardiness of the typical Western astronomer and the horribly restrictive and changing moderation of image size and post content (no PST mods?) on Cloudy Nights and the other popular forums out there. I was a beginner and I got nothing but a million reasons why I didn’t know what I was doing and none of my ideas for an outreach program would work, etc… lol “I aint got no time for dat foolishness”…so I just made my own forum.

I don’t use any sort of democratic process here, if I don’t like it and, in my opinion it promotes disharmony with the goals of CBSAP, I just remove them and their posts and that’s that. It works pretty good and has made for a pretty good ego free forum. lol

So, the single etalon Lunt LS80/B1200 is still my recommended scope for any serious astronomer wanting to get into the imaging part of this hobby with moderate financial means. I believe it is the best value on the market ($3300 US) for solar imaging and an excellent and rugged scope that will never need to be replaced. I suggest adding a 2nd internal etalon only after a few months of practicing your data acquisition and post processing skills.

A monochrome large chip (1600x1200+) CCD camera is still king in this hobby. There are plenty out there like the PGR’s and the DMK51s but I would suggest a CCD that is large enough to encompass a full disk image in the scope you are using to start with.

Currently, there is no company on Earth that makes a realistic, in house capture/process program for a Mac or a PC aimed at solar astronomy. You have to patch it together from different sources as none of the camera suppliers can afford to specialize in such a small part of the market and none of the software available works on a Mac in native OS X (OAS capture is pretty close to being awesome, but it still has no stacking component) . I use ASTRO IIDC with PGR Grasshopper cameras as does Alan Friedman but you cannot buy this software anymore. It was incredible but no one would pay for it so the guy took his skills eleswhere.

The Lunt LS80 single etalon scopes all come in around .6A resolution and provide plenty enough data to get any of the images you see here on this forum with the proper processing and camera.

Everyone has their opinions, that’s mine. I have a bit of experience in this.
Stephen W. Ramsden
Atlanta, GA USA
Founder/Director Charlie Bates Solar Astronomy Project
http://www.solarastronomy.org

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Re: Why bandwidth, why! (High Angstrom Fever)

Post by solarchat » Tue May 24, 2016 10:15 pm

I hope that we all go to a spectroheliograph setup with a multi platform interpolator that allows images in any wavelength directly on a preview screen but we are a long way off from that. Again, this is the future in my opinion.
Stephen W. Ramsden
Atlanta, GA USA
Founder/Director Charlie Bates Solar Astronomy Project
http://www.solarastronomy.org

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