Levenhuk Ra UHC 2 Filter Filter for observations of deep-sky objects. Barrel diameter: 2 Levenhuk Ra UHC 2 Filter is a good addition to your telescope for deep-sky observation under urban city illumination conditions. This filter suppresses up to 92% of city lights thanks to its 0.92 transmittance. This filter can be very helpful when it comes to astrophotography. With this filter you will be able to take incredible pictures of observed objects.