Experimenting calcium imaging with small refractors

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Experimenting calcium imaging with small refractors

Post by sywong2000 »

marktownley wrote: Wed Feb 02, 2022 6:27 am
sywong2000 wrote: Wed Feb 02, 2022 3:33 am Hi

I've been researching to start CaH or CaK imaging. From what I understand a scope with a good quality at UV range is needed.
How would you comment Tak FOA-60Q? I know a much cheaper synta 100mm ED may be better in terms of price-vs-performance.

I haven't seen much discussions using FOA-60Q in CaH/K nor Halpha. So just want to see if anyone may have thought using the scope for solar imaging?

Stephen
Hi Stephen.

Probably not to be honest. Just go for a Sky Watcher ED80 and stop it down to 60mm. The Tak is 2 or 3x the price of the SW.

Mark
Mark,

Thanks and it’s true that the Tak is pretty expensive, for the purpose. I owned a FC76DC for HA. The result is quite alright. However I checked the spot diagram and found the UV range of the 76DC is not very well. That’s why I’m researching if there’re other options for CaK/H. I’ll search and see how’s the performance of the 80ED, or may be just stick with the 76.

Thanks again for your advice!
Stephen


User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: Experimenting calcium imaging with small refractors

Post by Merlin66 »

Stephen,
I regularly use an ED80 stopped down to 60mm to give an f10 beam to the CaK filter.
Check out some of my results on the forum.
It certainly seems to work well for me.
My other alternative is my Custom Vixen 90/ 1000 which also works very well in CaK


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
sywong2000
Ohhhhhh My!
Ohhhhhh My!
Posts: 96
Joined: Sun Dec 27, 2020 4:26 pm
Location: Hong Kong
Has thanked: 230 times
Been thanked: 176 times

Re: Experimenting calcium imaging with small refractors

Post by sywong2000 »

Merlin,

Thank you. Yes I did searched around the forum and saw your results. Those are pretty nice. I think I would probably stay with my FC76D and then go for a Daystar Quark CaH... and try pushing it a little bit by trying different barlows and see how it goes...

I'm always looking for a 100mm-ish refractor in the 2nd hand market. However the only available items nearby my area is a brand new Celestron XLT 102 or 120. For SW, I cannot find the old version of Evostar anymore. I browsed around the forum and there're lot of useful information for me to understand what's needed for CaK/H. Until now I've found the CaK/H is a very "special" range of the spectrum for the commercial refractors to handle. Yet it'd be interesting to experiment with different setups.


User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: Experimenting calcium imaging with small refractors

Post by Merlin66 »

What ever you consider, the f10 requirement I think is mandatory for any of the CaK filters.


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
Post Reply