Baader Venus-UV filter (2")

The U- filter on the Baader U is a special filter that allows amateurs to capture atmospheric phenomena on Venus. Thanks to advanced coatings, the filter passes the 300-400 nm range, while blocking the 200-1500 nm range outside this range (photography in the deep UV wavelength range has generally been unavailable to amateurs.) The filter is only suitable for webcam or CCD observation, as the eye is insensitive to UV rays! To be successful, you need a UV sensitive camera and a telescope of at least 13 cm (20 cm for a webcam).