Solar Continuum Filter
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Re: Solar Continuum Filter
Because you are looking at the photosphere, not the chromosphere.
The green colored filter is narrowing down to 540nm in wavelength. This basically results in the edges of where the cracked glass appearance higher in contrast.
The green colored filter is narrowing down to 540nm in wavelength. This basically results in the edges of where the cracked glass appearance higher in contrast.
- Bob Yoesle
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Re: Solar Continuum Filter
You could use an H alpha filter (and many others) for WL continuum (photosphere) use as well. Either an off-band narrow (less than 0.1 nm) filter that is used for observation the chomosphere emission at 656 nm, or a much wider band ( 7 - 32 nm) nighttime H alpha filter could be used with a Herschel wedge, solar film, etc.
The Baader Continuum filter is specifically made to peak at 540 nm, as most telescopes are designed to provide their best visual performance and optical correction at that wavelength. This generally will give you very good contrast to best see sunspots, solar granulation, etc. of the photosphere.
The narrower H alpha and CaK filters are meant to see deeply into the the photosphere absorption line(s), where you will than see the emission line features of the chromosphere.
The Baader Continuum filter is specifically made to peak at 540 nm, as most telescopes are designed to provide their best visual performance and optical correction at that wavelength. This generally will give you very good contrast to best see sunspots, solar granulation, etc. of the photosphere.
The narrower H alpha and CaK filters are meant to see deeply into the the photosphere absorption line(s), where you will than see the emission line features of the chromosphere.
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Re: Solar Continuum Filter
As explained by Bob, you can take any filter to observe/image the photosphere.
As a general rule :
- the contrast of granulation increases when going to the blue end of the spectrum,
- turbulence increases when going to the blue end of the spectrum,
- some refractors have a lower optical quality in the blue,
- eye max sensitivity and vision of contrast is in the green.
As a general rule :
- the contrast of granulation increases when going to the blue end of the spectrum,
- turbulence increases when going to the blue end of the spectrum,
- some refractors have a lower optical quality in the blue,
- eye max sensitivity and vision of contrast is in the green.
Christian Viladrich
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Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
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Re: Solar Continuum Filter
Hi Bob,Bob Yoesle wrote: ↑Thu Feb 25, 2021 7:48 pm You could use an H alpha filter (and many others) for WL continuum (photosphere) use as well. Either an off-band narrow (less than 0.1 nm) filter that is used for observation the chomosphere emission at 656 nm, or a much wider band ( 7 - 32 nm) nighttime H alpha filter could be used with a Herschel wedge, solar film, etc.
The Baader Continuum filter is specifically made to peak at 540 nm, as most telescopes are designed to provide their best visual performance and optical correction at that wavelength. This generally will give you very good contrast to best see sunspots, solar granulation, etc. of the photosphere.
The narrower H alpha and CaK filters are meant to see deeply into the the photosphere absorption line(s), where you will than see the emission line features of the chromosphere.
The Sun MTMinc LR enhncd SM.jpg
Thank you very much for that image and explanation. Now I ask about the spicules and are these the transition zone NASA speaks about here ?
https://www.nasa.gov/mission_pages/iris ... erzoo.html
regards Rainer
Observatorio Real de 14
San Luis Potosi Mexico
North 22° West 101°
Observatorio Real de 14
San Luis Potosi Mexico
North 22° West 101°
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Re: Solar Continuum Filter
I use the 540nm filter a lot. It's a major part of my arsenal on studying the photosphere.
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Orion 70mm Solar Telescope
Celestron AstroMaster Alt/Az Mount
Meade Coronado SolarMax II 60 DS
Meade Coronado SolarMax II 90 DS
Meade Coronado AZS Alt/Az Mount
Astro-Tech AT72EDII with Altair solar wedge
Celestron NexStar 102GT with Altair solar wedge
Losmandy AZ8 Alt/Az Mount
Sky-Watcher AZGTI Alt-Az GoTo mount
Cameras: ZWO ASI178MM, PGR Grasshopper, PGR Flea
Lunt, Coronado, TeleVue, Orion and Meade eyepieces
Visual Observer
" Way more fun to see it! "