I'm the Coordinator of the Polisch Solar Observation Section. For my observations I use a 114 x 900 telescope with etched mirrors. Such equipment transmits about 0.8 to 1.4 beams of sunlight. I'm inserting an OIII filter into the eyepiece. The question is this.
Does this filter adequately protect against infrared radiation? I have not found any answer to this and I use this equipment for visual observation of the Sun. Greetings.
Telescope with etched mirrors
- marktownley
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Re: Telescope with etched mirrors
Greetings Tafig! By etched do you mean the coating has been removed from the mirror?
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: Telescope with etched mirrors
The comment Hello ! exactly sounds rather a RUDE comment and not needed
I hope I am wrong but it sounds dangerous what you are doing, I certainly would not want to be the one to use it
Just for info, if I ever come over as "blunt" or upset it is not intentional, I am AUTISTIC, I have Aspergers, and ADHD, Autism, so my apologies if I ever sound, unintentionally confrontational. Thank you
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Re: Telescope with etched mirrors
Such equipment transmits about 0.8 to 1.4 beams of sunlight
What does this mean ??????????
What does this mean ??????????
Just for info, if I ever come over as "blunt" or upset it is not intentional, I am AUTISTIC, I have Aspergers, and ADHD, Autism, so my apologies if I ever sound, unintentionally confrontational. Thank you
Esprit 120mm triplet refractor
Celestron Evolution Edge HD 8"
72mm Ed Skywatcher for Solar
SkyTee 2
Sky-Watcher SolarQuest
Gitzo Systematic Series 5
ASI 178MM
Daystar Quark Ha
WO Binoviewers
Many eyepieces 2"
Esprit 120mm triplet refractor
Celestron Evolution Edge HD 8"
72mm Ed Skywatcher for Solar
SkyTee 2
Sky-Watcher SolarQuest
Gitzo Systematic Series 5
ASI 178MM
Daystar Quark Ha
WO Binoviewers
Many eyepieces 2"
- marktownley
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Re: Telescope with etched mirrors
I think using with a uv/ir cut filter is not a bad idea.
http://brierleyhillsolar.blogspot.co.uk/
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Re: Telescope with etched mirrors
If both mirrors are etched about 4% of 4% enters your eye. OIII normally does not block above 1000nm. I would follow Mark's suggestion.
- marktownley
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Re: Telescope with etched mirrors
It's perfectly safe, there are quite a few people who have done it now. The uncoated mirror reflects a similar amount of light as a solar wedge transmits (assuming only the primary is uncoated). Therefore additional ND filtration is required to bring things down to a safe visual level, if imaging is the only consideration the more light the better as exposures will be shorter.
http://brierleyhillsolar.blogspot.co.uk/
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- tafig
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Re: Telescope with etched mirrors
OIII filters are not all the same. Photographic OIII filters give more protection than visual OIII filters. Still they usually block up to 1100-1200 nm.
Here is the example of the Astronomik CCD OIII :
So, as said before, it is better to associate the OIII with a neutral density filter, and if possible to an IR filter (KG3 or equivalent), in order to have blockage beyond 1100 nm. A good IR filter is the Beloptik IR filter.
Here is the example of the Astronomik CCD OIII :
So, as said before, it is better to associate the OIII with a neutral density filter, and if possible to an IR filter (KG3 or equivalent), in order to have blockage beyond 1100 nm. A good IR filter is the Beloptik IR filter.
Christian Viladrich
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/
Co-author of "Planetary Astronomy"
http://planetary-astronomy.com/
Editor of "Solar Astronomy"
http://www.astronomiesolaire.com/