The Baader Contrast Booster filter increases contrast and cuts the blue end of the spectrum, making surface detail on Jupiter, Mars, the Moon and the Sun (only with additional energy rejection). As most budget refractors are not very well corrected at these wavelengths, this filter corrects much of the false colour and allows you to make the most of the optics. It also cuts UV/IR, letting through light only where optics are their sharpest (especially with refractors). 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. They can even be put in front of a binoviewer without introducing astigmatism. The surfaces feature 7-layer Phantom Group and 23-layer dielectric UV/IR coatings to minimize ghosting, reflections and stray light scattering, which can ruin the fine details on planets. Note: Baader Neodymium filters are only 1mm thick, so will change backfocus requirements when used with more common 2-3mm thick imaging filters. This is because the absorption of the extra neodymium ions would be too great in thicker glass, which would lead to less brilliance in the resulting image. Available in either 1.25" or 2" 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. Specifications Transmission range Multiple bands - see spectrum image Type of filter Bandpass Usage Contrast enhancement, light pollution reduction AR-coating Phantom Group coating, planeoptically polished Filter thickness 1 mm (without cell), 6 mm with cell Filter size 1.25" / 2" mounted SKU BA2458360 (1.25"), BA2458365 (2")
