The Baader Methane 889nm Narrowband 8nm Filter is popular for planetary imaging and to increase contrast when imaging the Sun using the proper filtration. The optics are made of Schott RG830 glass, with super stack dielectric coatings for a pure 889nm methane band transmission. The glass is plane optically polished and hard coated for spectacular results and durability. The edges of the filter are sealed to resist aging.
Please note that a Methane filter is only meant for use with an imaging device, such as a webcam or CCD camera, since our eyes are not sensitive to this spectral region. An IR-sensitive CCD camera on a telescope with at least 5" of aperture or an IR-sensitive webcam with an 8"+ telescope is required for successful imaging with this extremely narrowband (8nm) filter.