What makes the Baader filters so unique? Through an extensive coating stack design and testing program, Baader has partnered with the world's leading thin film coating company to produce transmission curves that border on the ideal. Their ultra steep cutoffs and high transmission (>95%) allowed Baader to do something to a degree no other RGB filter set can manage - they are able to effectively separate the important H-Beta and O-III lines. The Baader Blue filter passes virtually all of the H-Beta and O-III lines, while the Green filter is able to capture all of the O-III line, without encroaching into the H-Beta line. None of the light is wasted by either filter. In this way, O-III is represented as it should be, a teal (blue-green) color, and H-Beta is captured solely in the blue. Never before has this degree of separation been achieved, and with such high transmission of both lines.