The Baader H-Alpha 35 nm (? 6,62,8 ?) screter combines images of the H-II regions with the highest contrast at the shortest possible exposure times. Its narrow band in the H-Alfa region has a transmission rate of over 95%. At the same time, it completely eliminates light pollution with anthropogenic light. The filter has been extremely precisely ground so that the surfaces are perfectly parallel and accurate to 1/4 the length of the wave over the entire surface. Multilayer dielectric coatings applied plasma and ionically cured are exceptionally hard and durable. The coatings in this filter are not damaged during normal use and cleaning.