Hello
I have for sale an IDAS UHB-RS 52mm ( front mounting ) Solar Filter.
Optical Density is rated as ND5.2 ( 1/160,000), it provides a neutral balance ( no color shift ) viewing.
This filter so impressed me that I bought the larger 82mm and for the last 10 or 11 years have used it as my white light photosphere filter and sold my 2 inch Herschel Prism.
This front mount filter threads directly onto the objective lens of my Borg 50mm Achromat scope.
I've checked the various web pages AstroHutech, Ted Astro and TANI where IDAS filters are listed and these UHB-RS are not listed, so maybe they are no longer available.
Euro 125 plus postage, or inspect and pick up from Vranic.
If you are interested in the Borg 50mm I could be persuaded to part with it.
Inspection welcome. Pickup from Vranic, 45 km from Belgrade, I can't deliver as I don't drive..
Reason for the sale is, I'm into my seventies and I'm downsizing to what I actually use.
Best Regards
Carl Dori
062 172 3837
carlddori@gmail.com