White light solar observations,questions..

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Pluton
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White light solar observations,questions..

Post by Pluton » Fri Sep 07, 2018 3:24 pm

Hello,
I have some important questions for me in relation to white light solar observing..:
- Using a Hershell prism to observe the sun in white light, is it better to use it in a refractor with ED or APO lens or is it the same if an achromatic refractor is used? Better with long focal length F8 or F10 or with an F6 also worth it? For example, in visual is a 4 "F / 9 or a 5" F6 better?
- From what aperture can we begin to have a detailed image with good resolution of details?
- And one last question, if you allow me, for visual observation to part of the filter ND3 and Top Pol, it is necessary to use a uv / IR filter in the eyepueces?
Regarding the Baader Continuum filter, does it really improve the contrast in visual, if so, from what aperture?
thank you very much in advance for your advice
regards
Paul

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marktownley
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Re: White light solar observations,questions..

Post by marktownley » Sat Sep 08, 2018 12:07 pm

The best way to use a wedge is with the continuum and uv/ir filter, with appropriate ND filtration. I always use a polarising filter on the eyepiece and then it is easy to adjust brightness just by rotating the ep. At the moment there is little to see in WL so a bigger aperture is better but your ultimate governing factor is your local seeing conditions.
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Pluton
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Re: White light solar observations,questions..

Post by Pluton » Sat Sep 08, 2018 4:18 pm

Hello,
Baader continuun filter is similar effect to a more normal green filter?
Which aperure you consider best for details in WL observation? then with a wedge is necessary a ND3, + Top Pol + UV/IV filter ? the Baader Continuun is optional ?
Best 2" wedge than a 1.25" o it´s indistinct
In WL observation is important one ED or APO refractor or an Acro sufficient ?
Again thanks for your advice.
Paul

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robert
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Re: White light solar observations,questions..

Post by robert » Sat Sep 08, 2018 4:45 pm

With narrowish band filter eg Baader Continuum an achromat is probably ok but best optical quality that is affordable is a good plan for detailed imaging in WL.
Without the narrow band filter APO will be better. Probably the wedge size is dependent on the camera chip size. Smaller CCD chip allows a smaller wedge 1.25" to work. I use 1.25" with PGR Ch3 camera and this is fine.
Aperture depends on what you are after. I use 80mm ED80 apo for full disks and 200mm Newtonian with astrosolar film ND3.8, for granulation. You need 100mm at least for granulation and good seeing.
Good luck
Robert
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