"The Baader Planetarium H-Alpha 35 nm CCD Filter (2"" eyepiece) allows for high-contrast deep sky images of the H-II regions. Ideal for interline CCD cameras, the 35 nm FWHM bandwidth of the H-Alpha filter makes this possible. The lower sensitivity of interline transfer CCDs benefits from the more efficient 35 nm FWHM.Compared to common-colored glass base filters, the sharp bandpass and >90% high efficiency coatings make the Baader H-Alpha filter superior amongst comparable filters. Like all Baader imaging filters, the H-Alpha filter shares all of the same outstanding features. Because of the high efficiency hardened multi-coatings and unmatched optical quality, the H-Alpha 35 nm CCD filter produces the sharpest and highest contrast images possible."