We have a public night next week, in town, so have dug out a couple of my filters to help decrease the pollution.
First is a Baader Narrowband O III Filter - this will help in polluted areas??
Have another, not sure what its for
- its a Knight Owl Filter #ND96-0.9 - hmmm .... think this is just a Moon filter.
Both are filthy, any special cleaning required?
Thanks
