In view of Solar CaII K line observations I made a new Solarfilm. My current solarfilm has a safety factor of 100.000 or ND5. As the CaII K line is located in the range of violet more light is needed. So instead of ND5 I will be using ND3.8.
How to make a solarfilm yourself? See my blog DIY Solarfilm.
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| My new Solarfilm ND3.8 8" |
