Baader Planetarium's 1.25" Single Polarizing Filter is designed for perfect light management when viewing bright objects. It reduces passing light by a factor of two. Reducing image brightness can help improve contrast in terrestrial viewing and imaging, especially in daytime photography. A polarizer also helps when viewing the Moon and planets by reducing brightness and glare to make it easier to see fine detail, or it can help split bright binary stars.
Baader's single polarising filter is a perfect complement for their solar Herschel wedge. A particularly handy attribute of the Herschel Wedge is its partial polarizing effect on the solar image. This permits a very convenient means of variably adjusting the image brightness, simply by using a single polarizing filter between the Herschel wedge and the eyepiece. The filter/eyepiece combination can then be rotated, and the image is variably dimmed which is very useful to easily achieve the optimum brightness for maximum visual contrast at any magnification.
This 1.25" filter (with M28.5x0.6 threads) is made for Baader in Japan, and it can be threaded on to 1.25" eyepieces directly.
Please Note: Polarizing filters are intended for visual use and if used for solar viewing, they must only be used in conjunction with the existing internal ND=3.0 filter in the Herschel wedge. A polarizing filter does not provide sufficient blocking by itself, nor is it able to block IR wavelengths as completely as an ND filter. Also, the polarizing filter must be used on the eyepiece or eyepiece reducer, never ahead of the ND3.0 filter (the polarizing filter must be located after the ND3.0 filter to prevent damage to the delicate internal layers of the polarizing filter).
Manufacturer part number: 2408343 or FPOL-1.