Scopes for solar imaging [Solar System] Acquisition techniques · Tareq Abdulla · ... · 25 · 568 · 0

TareqPhoto 2.94
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Hi all,

Are those scopes great for solar imaging? I want cheap scopes, cheap such as $100-200 for 80-100mm or $400-600 for 150mm aperture.

https://www.amazon.com/Orion-Compact-Refractor-Telescope-Optical/dp/B0779W98LL/ref=sr_1_1?crid=1CPWUNF6RO2G0&keywords=Orion+80mm&qid=1690317110&sprefix=orion+80mm%2Caps%2C278&sr=8-1

https://www.amazon.com/Orion-StarBlast-Altazimuth-Refractor-Telescope/dp/B07XKGKMRJ/ref=sr_1_3?keywords=102mm+telescope&qid=1690319540&sr=8-3

https://www.bresser.de/en/Astronomy/Telescopes/BRESSER-Messier-AR-90s-500-Optical-Tube-assembly.html

https://www.bresser.de/en/Astronomy/Telescopes/BRESSER-Messier-AR-152S-760-Hexafoc-Optical-Tube.html

https://www.ebay.com/itm/145133650995?var=444324889812
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andreatax 9.89
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White light or H-alpha? Anyways me thinks they are way too fast. Get a f/8 or a f/10 scope. TAL or Vixen are best.
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TareqPhoto 2.94
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andrea tasselli:
White light or H-alpha? Anyways me thinks they are way too fast. Get a f/8 or a f/10 scope. TAL or Vixen are best.

WL and Ha and CaK.

Well, i can stop those down, and add telecentric Barlow or say Powermate, i have 2x and 5x, also i posted fast because if they are good i could try use it for DSO with Ha only or Ha/OIII without stars, because i have two 90mm triplets, one for RGB, and one for SII/Lum, so i want third scope for Ha or Ha/OIII because i have a dual band filter, but i don't ignore solar as well, i mean either one scope for solar and another for DSO, or one scope for both as i don't want to swap a lot but i can try use it for both sometimes, 150mm i only can buy as achromatic and no plan for DSO, but 90mm-100mm are for solar or for DSO whatever, or 70-80mm for solar only, i won't go less than 90mm for DSO with two 90mm triplets.
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andreatax 9.89
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There is no "good" for achros unless they are VERY slow. And I'd use them only with a colored filter (e.g. R) for white light imaging. The fast achros are good for wide field viewing and guiding (maybe with a filter as well). Not sure I'd use them for any imaging except mono and that limited to G channel and possibly R. Stick to f/8 or better f/10. The TAL as well as the Vixen achros are still very good and can be found at bargain-basement prices in the used market.
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andreatax 9.89
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And no CaK.
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TareqPhoto 2.94
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andrea tasselli:
There is no "good" for achros unless they are VERY slow. And I'd use them only with a colored filter (e.g. R) for white light imaging. The fast achros are good for wide field viewing and guiding (maybe with a filter as well). Not sure I'd use them for any imaging except mono and that limited to G channel and possibly R. Stick to f/8 or better f/10. The TAL as well as the Vixen achros are still very good and can be found at bargain-basement prices in the used market.

So if an Achro of F/5 stopped down to F/10 isn't good?

Or F/5 achro with 2x telecentric Barlow or even 5x to make it F/25 isn't good?

Only using a mono camera for solar.
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TareqPhoto 2.94
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andrea tasselli:
And no CaK.

What or why no CaK?
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andreatax 9.89
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Tareq Abdulla:
So if an Achro of F/5 stopped down to F/10 isn't good?

Or F/5 achro with 2x telecentric Barlow or even 5x to make it F/25 isn't good?

Only using a mono camera for solar.


What good that would be? Just get a smaller, slower scope and save both money and weight and on top of that the performance it is very likely to be better anyway. Adding a barlow doesn't make the lens slower, you're just magnifying the image scale and consequently all the optical gremlins.
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andreatax 9.89
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Tareq Abdulla:
What or why no CaK?


Because the violet is very very poorly corrected  in a fast refractor and even worse if it is an achro doublet.
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TareqPhoto 2.94
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andrea tasselli:
Tareq Abdulla:
What or why no CaK?


Because the violet is very very poorly corrected  in a fast refractor and even worse if it is an achro doublet.

What do you recommend for CaK full disk? I can't buy expensive scope for that.
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EdDixonImages 3.82
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For solar imaging, other than white light versions, things tend to get pricey very quickly.  Lunt makes very good dedicated solar scopes, but they are not cheap.  One also needs a camera suitable for solar work.

Another option area is to use a smaller refractor scope and a Quark eyepiece attachment.  Mono cameras go well with that combo.  I use a Quark along with a William Optics Z61 scope and a ZWO ASI294MM camera.  This is a recent image I did with that combo:

https://www.astrobin.com/es7j8z/

There are other solar images in my Astrobin site with different cameras.

Many local astro clubs have loaner scopes you can use to try things out.  That’s where I started with a 40mm Coronado loaner.
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andreatax 9.89
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Tareq Abdulla:
What do you recommend for CaK full disk? I can't buy expensive scope for that.


Prepare to spend a lot of $$$$ then. Or drop it. Anything you already have is good enough for WL as far as I can see.
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torsinadoc
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If I had to drop to one scope for cak,ha I would keep my cheap 102/f11 achromat. It’s a very nice scope for all things solar
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torsinadoc
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Tareq Abdulla:
andrea tasselli:
Tareq Abdulla:
What or why no CaK?


Because the violet is very very poorly corrected  in a fast refractor and even worse if it is an achro doublet.

What do you recommend for CaK full disk? I can't buy expensive scope for that.

See my post above. I also respaced my 150/1200 refractor for UV and it works great but my seeing rarely supports anything above 100 mm in CaK. I also have a 80/11.3 achromat that is well corrected in calcium. I believe the bresser 127/1200 is well corrected in CaK but unless you have excellent seeing you will mask the aperture.
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TareqPhoto 2.94
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Ed Dixon:
For solar imaging, other than white light versions, things tend to get pricey very quickly.  Lunt makes very good dedicated solar scopes, but they are not cheap.  One also needs a camera suitable for solar work.

Another option area is to use a smaller refractor scope and a Quark eyepiece attachment.  Mono cameras go well with that combo.  I use a Quark along with a William Optics Z61 scope and a ZWO ASI294MM camera.  This is a recent image I did with that combo:

https://www.astrobin.com/es7j8z/

There are other solar images in my Astrobin site with different cameras.

Many local astro clubs have loaner scopes you can use to try things out.  That’s where I started with a 40mm Coronado loaner.

I already have mono cameras ready for solar and planetary and DSO, so this is not a matter at al, only scopes is what i need to finish, and i wanted cheap scopes because i read people using achromatic scopes for solar into great results, and i know that achro scopes are cheap so how much cheapest i can go for that.

I tested my SW ST80 before with Antlia Wedge that has CaK filter built inside and it was nice, only full of dust that i didn't know how to remove and didn't take flat frames for that, but the result itself is nice, but now i received my Lunt CaK module then Antlia is thing of the past now, i will keep it, i also have the Quark "Combo" version and of course white light, i want to buy individual scopes for each and not one scope for all, ST80 is one so one or two more for full disk then i move to larger scope for close ups.
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TareqPhoto 2.94
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andrea tasselli:
Tareq Abdulla:
What do you recommend for CaK full disk? I can't buy expensive scope for that.


Prepare to spend a lot of $$$$ then. Or drop it. Anything you already have is good enough for WL as far as I can see.

You still didn't mention which scope to use with CaK, you just said $$$, i didn't ask about CaK itself, i asked about a scope to connect with CaK.
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TareqPhoto 2.94
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Alan:
If I had to drop to one scope for cak,ha I would keep my cheap 102/f11 achromat. It’s a very nice scope for all things solar

The question is, can you get a full disk of the sun with this scope without doing mosaic?
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TareqPhoto 2.94
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Alan:
Tareq Abdulla:
andrea tasselli:
Tareq Abdulla:
What or why no CaK?


Because the violet is very very poorly corrected  in a fast refractor and even worse if it is an achro doublet.

What do you recommend for CaK full disk? I can't buy expensive scope for that.

See my post above. I also respaced my 150/1200 refractor for UV and it works great but my seeing rarely supports anything above 100 mm in CaK. I also have a 80/11.3 achromat that is well corrected in calcium. I believe the bresser 127/1200 is well corrected in CaK but unless you have excellent seeing you will mask the aperture.

I really don't worry about seeing at all, i am happy and lucky to live in a place where seeing is vary between excellent to poor and clear skies, so i can always find or have that great seeing for any kind of imaging, been years watching the sky so i know about our conditions here, every year i am able to have clear and nice seeing, so i only worry about the equipment an no limit, not about sky conditions, only light pollution is an issue but that is for DSO night imaging.

I have ST80, definitely for use, i am planning to buy something like Bresser 152/1200 or 152/760 and stop it down or any 150mm scope cheap later in future for close ups, but first i need to finish scopes for full disk without mosaic if possible for all three, Ha, CaK, and WL.
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torsinadoc
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Tareq Abdulla:
Alan:
If I had to drop to one scope for cak,ha I would keep my cheap 102/f11 achromat. It’s a very nice scope for all things solar

The question is, can you get a full disk of the sun with this scope without doing mosaic?

Yes with zwo 1600
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TareqPhoto 2.94
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Alan:
Tareq Abdulla:
Alan:
If I had to drop to one scope for cak,ha I would keep my cheap 102/f11 achromat. It’s a very nice scope for all things solar

The question is, can you get a full disk of the sun with this scope without doing mosaic?

Yes with zwo 1600

Ok, cool, thank you very much
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TareqPhoto 2.94
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Well, for WL it is kind of easy, and for CaK i saw two imagers here on Astrobin using the exact same scope with exact same CaK filter that i also have but each with different cameras [i believe i have the same of one of them and not the other but similar], the scope is not expensive but it is not cheap being a doublet ED and slow [F/10], so i didn't think about buying this unless if i wait until say November then i can buy it then i never look back and solve two solar imaging filters.

For Ha with Quark i feel it needs a bit more care, they mentioned i must operate it at F/15 up to F/30 for best performance, so maybe i will look for a doublet scope and use my Powermate to reach F/15-F40 and see how it will perform, maybe something like 50mm/60mm aperture, another one than what i have to be only for solar, or if a bit larger like 80-100mm then i have to think about using my 0.5x reducer then in the setup.
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andreatax 9.89
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The Quark (prominence) , which I had, has a 4x focal extender (telecentric) incorporated within the body of the filter and I used it with my f/7.5 APO without major issues, except the actual resulting image scale was far more than my seeing could afford.
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TareqPhoto 2.94
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andrea tasselli:
The Quark (prominence) , which I had, has a 4x focal extender (telecentric) incorporated within the body of the filter and I used it with my f/7.5 APO without major issues, except the actual resulting image scale was far more than my seeing could afford.

My Quark [Chromosphere] is the Combo version, which is without, so i must use a telecentric Barlow, i have Powermate 2x and 5x, so if i will use 5x then i should use a scope with f/5 or f/6 then to reach f/25-f30.
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andreatax 9.89
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As far as I know the Powermate 5x isn't telecentric. At least mine isn't.
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TareqPhoto 2.94
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andrea tasselli:
As far as I know the Powermate 5x isn't telecentric. At least mine isn't.

You know what, i wish if the language English can make the definitions very straight forward and clear to make it sense so we are non English people know what we read.


Powermate:
https://www.televue.com/engine/TV3b_page.asp?id=53&Tab=_back


Telecentric Barlow:
https://www.baader-planetarium.com/en/blog/the-benefits-of-telecentric-systems/

Mentioning about a positive lens or optics to redirect the light ray or beam, any kid will understand that they are both the same concept, if others say otherwise then i give up and leave to another planet.
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