There are an unfortunate number of them in the world and lasers are increasingly cheap and plentiful.
There are an unfortunate number of them in the world and lasers are increasingly cheap and plentiful.
Desire to own shades with deep, narrow notch filters at multiple specific frequencies[*] intensifies... [*] If such a thing exists; my knowledge of filters starts with RC, LC and crystal filters, petering out somewhere around rectangular plumbing.
They do. They are often much more of a pain than they’re worth. And quite expensive.