Baader Planetarium Narrowband Oxygen-III Filter 8.5nm 50.4mm
|Baader Planetarium un-mounted 50.4 mm Narrowband Oxygen-III CCD filters deliver outstanding transmission with a sharp and narrow 8.5nm bandpass. |
CCD imagers will find Baader's Premium Narrowband CCD pass filters to deliver the absolute highest contrast deep sky images in H-Alpha, H-Beta, Oxygen III, and Sulfur-II, with the shortest exposures possible. Their ultra-narrow bandwidths have extremely high transmissions, while completely rejecting light pollution as well as the important blocking of longer wavelengths.
The high optical quality of the Baader narrowband filters guarantees no loss in sharpness or contrast. Each substrate is fine-optically polished plane parallel to deliver a smooth and accurate 1/4 wavefront over the entire surface. This special custom polishing operation sets Baader filters apart from the standard commercially precision polished filter substrates used by most other filter manufacturers.
In addition to their transmission properties, the Baader coatings were developed with another key goal in mind - eliminate the annoying reflections present in other narrowband astro-filters. To achieve this freedom from reflections, along with excellent out of band blocking, required careful design and testing of the coating stacks.