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?
Omega Optical CaH filter
- GreatAttractor
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- Merlin66
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Re: Omega Optical CaH filter
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
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
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"Astronomical Spectroscopy for Amateurs" and
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https://groups.io/g/astronomicalspectroscopy
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
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Re: Omega Optical CaH filter
Why?
They work for me......
They work for me......
"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
https://groups.io/g/astronomicalspectroscopy
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
- Valery
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Re: Omega Optical CaH filter
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
Here is this filter unevenness in CWL. I stacked it with Lunt etalon.
Valery
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"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.
Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.
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Re: Omega Optical CaH filter
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
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
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.
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.io/g/astronomicalspectroscopy
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
https://groups.io/g/astronomicalspectroscopy
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
- GreatAttractor
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Re: Omega Optical CaH filter
Thank you everyone for input. CaK imaging is a plan for the future anyway, it's Hα for me right now.