The Baader Methane filter is an 8nm narrowband photographic filter designed to isolate the CH4 band at 889nm. This is useful for capturing finer details and contrast on Jupiter and Saturn. As the human eye is not sensitive to light beyond 700nm, this is strictly a photographic filter and benefits from cameras with good NIR response such as the ZWO ASI662MC.
The optical surface is fine-optically polished so that there is no loss of sharpness at high magnifications, even when the filter is positioned far in front of the focal point. The filter is made from a Schott RG 830 substrate with "super stacked" dielectric coatings for pure transmission.
Available in 1.25" mounted. The filter cell is threaded on both ends so that multiple filters can be stacked. All Baader filters (excluding 100 x 100mm) come in stackable labelled filter boxes which can be attached to each other to form a sturdy filter library.
Dielectric coating, planeoptically polished
|2 mm (without cell), 6 mm with cell