What do you think about this CaK combo?
What do you think about this CaK combo?
I have come across an optical manufacturer that can provide me with the attached filters for a CaK scope.
I am waiting for the price quote, however, what are your thoughts about the specifications?
I am waiting for the price quote, however, what are your thoughts about the specifications?
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- marktownley
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Re: What do you think about this CaK combo?
Way too wide a bandpass to show CaK detail.
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Re: What do you think about this CaK combo?
Mark, yes I agree, but this will be used in conjunction with Bob's new CaK filter. So the above will only be used as blocking and energy reduction...
Re: What do you think about this CaK combo?
So the optical train will be: dichroic mirror, broadband filter, narrowband CaK, camera.
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Re: What do you think about this CaK combo?
Hi Brett
That may be useful as a prefilter, check out the price against a K-Line filter and please report
That may be useful as a prefilter, check out the price against a K-Line filter and please report
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE
from 7 am - 7 pm http://www.nanosys.ch
from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa
from 7 am - 7 pm http://www.nanosys.ch
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Re: What do you think about this CaK combo?
Are the filters you have sourced designed for energy rejection or 'visual' use? Even on the context of imaging I am including the tag of 'visual' use.
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Re: What do you think about this CaK combo?
Walter, I will keep this thread up to date as I get more info and prices.
Mark, the filters above are used as energy rejection. On their own they should not be used for visual. But, if my thinking is correct, when used in conjunction with the Omega CaK filter, it should be safe for visual. The Omega CaK safely reduces down to ND5. For 100% safety for visual use, I would check the transmission of everything carefully. At this stage for visual use I am not 100% sure. However, my aim is to image in CaK anyway.
Mark, the filters above are used as energy rejection. On their own they should not be used for visual. But, if my thinking is correct, when used in conjunction with the Omega CaK filter, it should be safe for visual. The Omega CaK safely reduces down to ND5. For 100% safety for visual use, I would check the transmission of everything carefully. At this stage for visual use I am not 100% sure. However, my aim is to image in CaK anyway.
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Re: What do you think about this CaK combo?
What i'm getting at Brett is if the filters were originally designed to be used in say laser systems or the like for energy rejection, then optically (through the camera or visually, it does not matter) you may find that they are not optically flat or suffer from internal ghosting which has a detrimental effect. A Baader filter on the other hand are designed for visual use (be it at the eyepiece or with a camera) and as a result is optically flat and the reflections between the different filter elements are controlled.
This is why myself or Walter keep on about using a Baader K line. There is no benefit to using cheaper substitutes.
This is why myself or Walter keep on about using a Baader K line. There is no benefit to using cheaper substitutes.
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
Re: What do you think about this CaK combo?
Ah, okay Mark, I get what you are saying. Yes, the flatness and AR elements are important. However, the manufacturer can machine according my specs. I have told them that it will be for an astromical telescope used for imaging the Sun. So optical flatness should be in the 1/10L area.
I realize of course that the Baader K line is probably the best option at this stage, but it would be nice though if we could get an affordable alternative. Or better for the same price. This is why I asked about Bobs CaK as a blocker in another thread.
I realize of course that the Baader K line is probably the best option at this stage, but it would be nice though if we could get an affordable alternative. Or better for the same price. This is why I asked about Bobs CaK as a blocker in another thread.
- Merlin66
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Re: What do you think about this CaK combo?
I have one of Bob's earlier 40A CaK filters and I'm waiting on his 2A version.
I intend to combine them for CaK imaging.
No additional filtering.
I intend to combine them for CaK imaging.
No additional filtering.
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
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"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
Re: What do you think about this CaK combo?
Merlin, will you mind providing me with a link to his earlier 40A version filters?
- marktownley
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Re: What do you think about this CaK combo?
Just make sure they are designing the optical flatness at 393nmBrett wrote:the manufacturer can machine according my specs. I have told them that it will be for an astromical telescope used for imaging the Sun. So optical flatness should be in the 1/10L area.
I've bought a lot of filters from Bob and also from Baader, at the end of the day you pay your money and take your choice. The Baader filters have always performed considerably better than Bobs, just depends what results you are happy with.Brett wrote:I realize of course that the Baader K line is probably the best option at this stage, but it would be nice though if we could get an affordable alternative. Or better for the same price. This is why I asked about Bobs CaK as a blocker in another thread.
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Re: What do you think about this CaK combo?
Brett,
Correction - it was an 80A FWHM filter.....
#0391BP010-001
Purchased a couple of years ago from Bob. You'd need to check with him, re current availability.
Correction - it was an 80A FWHM filter.....
#0391BP010-001
Purchased a couple of years ago from Bob. You'd need to check with him, re current availability.
"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
Re: What do you think about this CaK combo?
Thanks Merlin, are you referring to this one:
http://www.ebay.com/itm/Optical-Filter- ... 2331133f62
http://www.ebay.com/itm/Optical-Filter- ... 2331133f62
- Merlin66
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Re: What do you think about this CaK combo?
Yeah, that looks like the one I have.
"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
- marktownley
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Re: What do you think about this CaK combo?
Brett, I have one of these. You can use it, it will work, but I can categorically tell you there are far better alternatives. These filters are designed for energy rejection not imaging / visual use (like the omega CaK, and probably also the CaH filter, I would speculate based on Walters images). There's a reason why coronado and Lunt use a totally different design of filter than this. if you want it drop me an address via email and i'll post it to you i'm not going to use it.
http://brierleyhillsolar.blogspot.co.uk/
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Re: What do you think about this CaK combo?
Hi Brett
Mark is the top CaK modder, belive him. If he is not convinced, don't buy, If Mark and I disagree, don't buy eighter
Mark is the top CaK modder, belive him. If he is not convinced, don't buy, If Mark and I disagree, don't buy eighter
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE
from 7 am - 7 pm http://www.nanosys.ch
from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa
from 7 am - 7 pm http://www.nanosys.ch
from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa
Re: What do you think about this CaK combo?
Mark thank you for your offer. I have sent you a mail with my address. Let me know if you did not get it.
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Re: What do you think about this CaK combo?
Hi brett, Yes, have received it. I will get the filter in the post to you.
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!