The Baader Double Polarizing filter is useful for reducing the brightness and glare of objects such as the Moon or the Sun (only with additional energy rejection filter), as well as increasing contrast on the planets while maintaining a neutral colour balance. The front filter can be rotated to adjust the brightness to a comfortable level. Warning: Polarizer and neutral density filters need additional filtering (for example, Baader Herschel Prism or Baader Astro Solar Safety Film) before the eyepiece of the telescope for observations of the sun. Using without the appropriate filters can cause damage to the these filters and eyesight. The optical surface of 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. Like all Baader filters, the surfaces feature 7-layer Phantom Group coatings to minimized ghosting, reflections and stray light. Available in either 1.25" or 2" mounted. The filter cell is threaded on both ends so that multiple filters can be stacked (such as Baader colour planetary filters). 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 Full spectrum Special features Double polarizing for stepless brightness adjustment Optical density 0.6 - 3.0 AR-coating Phantom Group coating, planeoptically polished Filter thickness 2 mm (without cell), double mounted for 15 mm total height with cell Filter size 1.25" / 2" mounted SKU BA2408340 (1.25"), BA2408344 (2")
