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Re: Calcium k-line blocking filter / ERF - quest off the she

Posted: Tue Apr 05, 2016 8:16 am
by marktownley
I have the 387/11 and use it in my CaK filter (and also thor coated KG3!). That slope definitely has a positive effect in terms of image contrast.

I think the one to add would be one of the andover 1nm 393nm filters ... s-filters/