Hi,
anything from the Lee sortiment is for imaging and thus NOT to be used for visual observation under any circumstances - especially if you don't know a lot about visual solar observation!
The filter material MUST be designed for visual observation through an instrument, like the Baader Astrosolar Film. Filter material for imaging has a transmission about an order of magnitude higher for the visual range and does not care about any wavelengths that imaging sensors don't detect and WILL RUIN your eyesight!
Please also note that there is also a difference between filter material suitable for visual observation through instruments and the stuff for naked eye observation (e.g. eclipse goggles)! The latter must also shield well for parts of the spectrum which are filtered by optical glass, e.g far infrared.
AstroSolar® Safety Film 5.0 for solar observation and photography at high magnification, telescope quality, Optical Density (OD) = 5.0Safe for visual solar observation (with additional optics) and imagingThis highest precision film consistently produces s
www.baader-planetarium.com
It seems Baader now has ready to use filters for spotters with their visual film at quite competitive prices...
Cheers,
Joachim