Celestron 1.25" ND09 Neutral Density Lunar Filter

This neutral density filter attenuates light evenly across the entire optical spectrum, making it perfect as a lunar filter for large telescopes with an aperture of 200 mm or more.

Apart from lunar observation, it is also used to separate binary stars when one of them is considerably brighter than the other. This neutral density filter also increases contrast for observing Venus and Jupiter. Specifically, the phases of Venus are much better appreciated with it.

Unlike lunar filters, which are actually color filters, this neutral density filter preserves the natural tone. Also called gray filter.

Simply screw it into the filter thread of the insertable socket of the eyepiece or a planetary camera.