DIY heat sink for Herschel wedge builders
- Merlin66
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DIY heat sink for Herschel wedge builders
I've just received a Ceramic tile with small holes, 2-5/8" sq. x 1/2" thk., #M3156 from Surplus Shed.
I think this could make a great rear heat sink for a DIY Herschel wedge.
I think this could make a great rear heat sink for a DIY Herschel wedge.
"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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http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
Re: DIY heat sink for Herschel wedge builders
Hi Ken,
I hope you do not think me being condescending by asking, but have you built a DIY Herschel Weddge before. I would be very interested in how to go about it.
I hope you do not say "Yes, i have a comprehensive PDF file on how to do it". The last time you said something like that to me I ended up putting together a TAL 100RS PST Stage 2 and lightened my pocket by a considerable sum
Ian
I hope you do not think me being condescending by asking, but have you built a DIY Herschel Weddge before. I would be very interested in how to go about it.
I hope you do not say "Yes, i have a comprehensive PDF file on how to do it". The last time you said something like that to me I ended up putting together a TAL 100RS PST Stage 2 and lightened my pocket by a considerable sum
Ian
Re: DIY heat sink for Herschel wedge builders
Hold on to your wallet Ian, the answer is coming for sure.
Allan
- Merlin66
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Re: DIY heat sink for Herschel wedge builders
http://solarchat.natca.net/index.php/en ... ge-take-ii
If you can find a suitable prism wedge and use an existing 2" diagonal it's not that expensive - much much cheaper than the Baader or Lunt offerings.
If you can find a suitable prism wedge and use an existing 2" diagonal it's not that expensive - much much cheaper than the Baader or Lunt offerings.
"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: DIY heat sink for Herschel wedge builders
Doh, I knew i should not have posted that reply to Ken's original - and to top it all I clicked on the link Ken posted in his reply
Don't worry, i am not about to dash out and persue this avenue - just yet
Ken,
I do not doubt your knowledge and ingenuity, but my pocket has a distinct dislike for your posts :unsure:
Ian
Don't worry, i am not about to dash out and persue this avenue - just yet
Ken,
I do not doubt your knowledge and ingenuity, but my pocket has a distinct dislike for your posts :unsure:
Ian
Re: DIY heat sink for Herschel wedge builders
There is a ATM on the Cloudy Nights ATM forum that has published grinding your own 15 deg prism instructions. I don't have a link but their search engine should find it.
- DSobserver
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- Merlin66
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Re: DIY heat sink for Herschel wedge builders
No,
I just used it visually on a TS102 refractor...
It performed very well.
I just used it visually on a TS102 refractor...
It performed very well.
"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
- Bob Yoesle
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Re: DIY heat sink for Herschel wedge builders
There is a ATM on the Cloudy Nights ATM forum that has published grinding your own 15 deg prism instructions.
You don't really need to use a wedge prism for a solar filter application. In fact, you can just reverse the right angle prism form any standard diagonal and do the same thing as a wedge prism:
I would blacken the side opposite from the eyepiece with a good flat black paint job...
You still need to use the ND 3 and ancillary filters AFTER THE REFLECTION to achieve a safe level of filtering. And you could incorporate any of the similar methods of venting &/or cooling to enclose the prism housing... such as a CPU heat sink, TEC, etc.
Bob B)
You don't really need to use a wedge prism for a solar filter application. In fact, you can just reverse the right angle prism form any standard diagonal and do the same thing as a wedge prism:
I would blacken the side opposite from the eyepiece with a good flat black paint job...
You still need to use the ND 3 and ancillary filters AFTER THE REFLECTION to achieve a safe level of filtering. And you could incorporate any of the similar methods of venting &/or cooling to enclose the prism housing... such as a CPU heat sink, TEC, etc.
Bob B)
Diagonally parked in a parallel universe.
Curiosity is the father of knowledge; uncertainty is the mother of wisdom.
Dark-Sky Defenders
Goldendale Observatory
Curiosity is the father of knowledge; uncertainty is the mother of wisdom.
Dark-Sky Defenders
Goldendale Observatory
- swisswalter
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Re: DIY heat sink for Herschel wedge builders
Hi Bob
thank you for the information.
thank you for the information.
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: DIY heat sink for Herschel wedge builders
There is a ATM on the Cloudy Nights ATM forum that has published grinding your own 15 deg prism instructions.
You don't really need to use a wedge prism for a solar filter application. In fact, you can just reverse the right angle prism form any standard diagonal and do the same thing as a wedge prism:
I would blacken the side opposite from the eyepiece with a good flat black paint job...
You still need to use the ND 3 and ancillary filters AFTER THE REFLECTION to achieve a safe level of filtering. And you could incorporate any of the similar methods of venting &/or cooling to enclose the prism housing... such as a CPU heat sink, TEC, etc.
Bob B)
That is good rough math but if an error of 10% in throughput matters then make sure to study Brewster's Angle. I like the idea.
You don't really need to use a wedge prism for a solar filter application. In fact, you can just reverse the right angle prism form any standard diagonal and do the same thing as a wedge prism:
I would blacken the side opposite from the eyepiece with a good flat black paint job...
You still need to use the ND 3 and ancillary filters AFTER THE REFLECTION to achieve a safe level of filtering. And you could incorporate any of the similar methods of venting &/or cooling to enclose the prism housing... such as a CPU heat sink, TEC, etc.
Bob B)
That is good rough math but if an error of 10% in throughput matters then make sure to study Brewster's Angle. I like the idea.
- swisswalter
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Re: DIY heat sink for Herschel wedge builders
Hi Colin
that is an interesting response. How would I construct a wedge having say 10 or 20% reflection? I'm always missing light when I'm doing close ups in WL and CaK
that is an interesting response. How would I construct a wedge having say 10 or 20% reflection? I'm always missing light when I'm doing close ups in WL and CaK
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
- Merlin66
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Re: DIY heat sink for Herschel wedge builders
Walter,
can't be done with a bare prism...the maximum reflection is around 4%.
To get any higher the front surface would have to be partially reflective coated, or use a 10/90 or 20/ 80 beamsplitter plate....
can't be done with a bare prism...the maximum reflection is around 4%.
To get any higher the front surface would have to be partially reflective coated, or use a 10/90 or 20/ 80 beamsplitter plate....
"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: DIY heat sink for Herschel wedge builders
Walter this will be an easy read for you:
http://en.wikipedia.org/wiki/Brewster's_angle
You can adjust the reflectivity and it is quite polarization dependent but Ken is right you will not increase it.
http://en.wikipedia.org/wiki/Brewster's_angle
You can adjust the reflectivity and it is quite polarization dependent but Ken is right you will not increase it.
- swisswalter
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Re: DIY heat sink for Herschel wedge builders
Hi Ken, Hi Colin
thank you very much. Now I have things to go after. I guess I have to start with a 10% beamsplitter
thank you very much. Now I have things to go after. I guess I have to start with a 10% beamsplitter
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
- marktownley
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Re: DIY heat sink for Herschel wedge builders
A 45 degree hot mirror is what you need walter - i'm having the same closeup problems in WL @ CaK too. There's a few options on Edmunds Optics site i've been considering. I'll fish out some links for you later on, got to go and get ready for work now...
http://brierleyhillsolar.blogspot.co.uk/
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Re: DIY heat sink for Herschel wedge builders
Mark,
I think you mean a Cold mirror...
http://www.edmundoptics.com/optics/opti ... rrors/1900
Problem is that they reflect 80% of visual - too much for a wedge application....
Plenty of beamsplitter plates to choose from.
http://www.edmundoptics.com/optics/beam ... tters/2035
(I use them for guiding on the spectrosocope - a "special" 4r/92t)
I think you mean a Cold mirror...
http://www.edmundoptics.com/optics/opti ... rrors/1900
Problem is that they reflect 80% of visual - too much for a wedge application....
Plenty of beamsplitter plates to choose from.
http://www.edmundoptics.com/optics/beam ... tters/2035
(I use them for guiding on the spectrosocope - a "special" 4r/92t)
"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: DIY heat sink for Herschel wedge builders
How would I construct a wedge having say 10 or 20% reflection? I'm always missing light when I'm doing close ups in WL and CaK
The obvious solution is to use a lighter ND filter after the wedge ...
The obvious solution is to use a lighter ND filter after the wedge ...
- swisswalter
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Re: DIY heat sink for Herschel wedge builders
Hi Mark, Ken and Brian
thank you very much for your help
@Brian I'm not using any ND filter at all after the wedge
@Mark I'll be lookng forward to your findings
@Ken I'll have to look into the beamsplitter plates, thank's for the link
thank you very much for your help
@Brian I'm not using any ND filter at all after the wedge
@Mark I'll be lookng forward to your findings
@Ken I'll have to look into the beamsplitter plates, thank's for the link
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
- marktownley
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Re: DIY heat sink for Herschel wedge builders
Mark,
I think you mean a Cold mirror...
http://www.edmundoptics.com/optics/opti ... rrors/1900
Problem is that they reflect 80% of visual - too much for a wedge application....
Nope, I most definitely mean a hot mirror http://www.edmundoptics.com/optics/opti ... rrors/1492
As you note cold mirrors reflect 80% of the visual, that's no good - that is what we're trying to keep.
I'm not going to use this with a wedge, I intend using instead of a wedge
Walter and I are already using shortpass/longpass filter combinations with our CaK rigs. The aim is to be able to image at several metres focal length in CaK, yet still keep the exposure shorter than 1/1000second. Imaging at 1/77s or 1/250s in CaK wavelengths at these silly focal lengths just introduces blurring as a result of the seeing. If you can image at ~1/5000th sec exposure things are much improved. You should know by now Ken we're not trying to do anything sensible
I think you mean a Cold mirror...
http://www.edmundoptics.com/optics/opti ... rrors/1900
Problem is that they reflect 80% of visual - too much for a wedge application....
Nope, I most definitely mean a hot mirror http://www.edmundoptics.com/optics/opti ... rrors/1492
As you note cold mirrors reflect 80% of the visual, that's no good - that is what we're trying to keep.
I'm not going to use this with a wedge, I intend using instead of a wedge
Walter and I are already using shortpass/longpass filter combinations with our CaK rigs. The aim is to be able to image at several metres focal length in CaK, yet still keep the exposure shorter than 1/1000second. Imaging at 1/77s or 1/250s in CaK wavelengths at these silly focal lengths just introduces blurring as a result of the seeing. If you can image at ~1/5000th sec exposure things are much improved. You should know by now Ken we're not trying to do anything sensible
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!
- Bob Yoesle
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Re: DIY heat sink for Herschel wedge builders
Hi Mark,
As another source for hot mirrors (and other optics), you might be interested in Thor Labs:
http://www.thorlabs.com/navigation.cfm?guide_id=2234
In addition to Colin's link, another good tutorial on reflection / refraciton can be found here:
http://en.wikipedia.org/wiki/Fresnel_equations ;
and here:
http://www.telescope-optics.net/reflection.htm
Bob B)
As another source for hot mirrors (and other optics), you might be interested in Thor Labs:
http://www.thorlabs.com/navigation.cfm?guide_id=2234
In addition to Colin's link, another good tutorial on reflection / refraciton can be found here:
http://en.wikipedia.org/wiki/Fresnel_equations ;
and here:
http://www.telescope-optics.net/reflection.htm
Bob B)
Diagonally parked in a parallel universe.
Curiosity is the father of knowledge; uncertainty is the mother of wisdom.
Dark-Sky Defenders
Goldendale Observatory
Curiosity is the father of knowledge; uncertainty is the mother of wisdom.
Dark-Sky Defenders
Goldendale Observatory