Double stack - a standard etalon?

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Bassoon
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Double stack - a standard etalon?

Post by Bassoon » Sun Nov 27, 2016 10:21 am

I have a Coronado 60 II double stack, also a 102mm stage 2 using a PST etalon.

I'm not sure about an exact description of the 60's double stack unit - is it a second etalon? If so could it be used on its own (with an ERF and blocking filter) on a much larger scope? Or is the principle of the double stack filter different to a standard etalon?

If it is an etalon, with its larger diameter would it offer the chance to mod a much larger aperture?

Coronado says it's double stack kits must not be used 'on their own'. I presume they mean without a blocking filter - or are they not etalons?

Any advice to avoid me burning my retina would be appreciated!

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Bob Yoesle
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Re: Double stack - a standard etalon?

Post by Bob Yoesle » Sun Nov 27, 2016 4:11 pm

Hydrogen alpha solar telescopes are a complex "stew" of filters and optics, and one can easily create something that would not work properly or be safe. Honestly - and not trying to be anything but helpful to preserving your retina - given that you don't apparently know what you are currently using and how it works, I would be hesitant to encourage your attempting use either the front or internal etalon to "mod a much larger aperture."

The Coronado 60 II double stack telescope consists of a front etalon with ERF, rich-view and tilt tuning, and an internal etalon/collimator system with rich-view tuning. The front etalon should be usable on another instrument if paired with the blocking filter, though it may be tuned with a bit higher CWL to allow additional tilting to remove retro-reflections between etalons. From much personal experience, the interal etalon and collimator optics would need a dedicated IR and UV blocking ERF and much more complex and difficult engineering to get right.

I advise that you save up and get yourself a ready made 80 to 152 mm solar telescope - a used scope will save you a lot of $$$. ;)
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Bassoon
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Re: Double stack - a standard etalon?

Post by Bassoon » Sun Nov 27, 2016 4:53 pm

Hi Bob
Thanks for the advice.
Regards, John

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