The Baader Fringe Killer Filter is a high quality UV/IR block which also removes violet and some blue light. Perfect for imaging and visual use with the smaller fast Chinese achromats and many semi-apos.
Midway between the Astronomik CLS and UHC in terms of bandpass, the Baader UHC-S Filter is best used visually by owners of smaller telescopes (8″ or less) for nebular observation or for general observation in areas of high light pollution.
Owners of larger scopes and imagers will get better results with the Astronomik UHC.