Omega Optical CaH filter

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GreatAttractor
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Omega Optical CaH filter

Post by GreatAttractor » Sat May 12, 2018 8:00 am

I was browsing through Omega Optical filters on Ebay and noticed this:

Optical Filter Astronomy 396.9SC0.2 Ca H filter 1.25"

(full description: link)

CaH with 2 Å bandwidth and 90% transmission for $300. Seems promising, what do you think?
My software:
Stackistry — an open-source cross-platform image stacker
ImPPG — stack post-processing and animation alignment
My images

SW Mak-Cass 127, ATM Hα scope (D=90 mm, LS50 etalon), Lunt LS50THa, ATM SSM, ATM Newt 300/1500 mm, PGR Chameleon 3 mono (ICX445)

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Merlin66
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Re: Omega Optical CaH filter

Post by Merlin66 » Sat May 12, 2018 1:50 pm

I’m trialing a stacked combo of three Omega CAK filters (see my other thread)
So far the results have been promising.viewtopic.php?f=9&t=23536
"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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Merlin66
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Re: Omega Optical CaH filter

Post by Merlin66 » Sun May 13, 2018 2:07 pm

Why?
They work for me......
"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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Valery
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Re: Omega Optical CaH filter

Post by Valery » Mon May 14, 2018 12:14 am

My experience with Omega is rather poor. The filter he sent me is the worst optical detail I have ever saw.

Here is this filter unevenness in CWL. I stacked it with Lunt etalon.


Valery
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Montana
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Re: Omega Optical CaH filter

Post by Montana » Mon May 14, 2018 6:55 am

I have one of those, it is optically clear but I didn't see much difference with it. I don't use it anymore.

https://www.flickr.com/photos/alexandra ... 0715279858

I must admit I tried it with the SCT and the Baader solar film and I couldn't see anything at all, does Baader film cut below 400nm? it works great with the solar wedge. I can sell you mine for a cheap price if you like? but you probably don't want it :)

Alexandra

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Re: Omega Optical CaH filter

Post by Merlin66 » Mon May 14, 2018 7:50 am

Alexandra,
The ND 3,8( or the ND 5) filtering extends into the UV.....
Just not enough light getting through to the filter - as you say, works well with the wedge.
"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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GreatAttractor
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Re: Omega Optical CaH filter

Post by GreatAttractor » Mon May 14, 2018 4:45 pm

Thank you everyone for input. CaK imaging is a plan for the future anyway, it's Hα for me right now.
My software:
Stackistry — an open-source cross-platform image stacker
ImPPG — stack post-processing and animation alignment
My images

SW Mak-Cass 127, ATM Hα scope (D=90 mm, LS50 etalon), Lunt LS50THa, ATM SSM, ATM Newt 300/1500 mm, PGR Chameleon 3 mono (ICX445)

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