The Universal Filter Changer, UFC: The Baader UFC system is a filter drawer that can be used for a wide variety of telescope and camera systems with a sufficiently large connection diameter, which at the same time is extremely short but also accepts filter sizes up to 50x50mm without vignetting. These properties are a prerequisite for the new, fast optics such as. B. EdgeHD telescopes with Hyperstar and the new RASA devices from Celestron, as well as all other Prime Focus astrographs with suitable filters, on which a regular filter wheel would shade too much of the front opening. In addition, prime focus optics are inevitably equipped with a very short back focus and require a particularly space-saving filter drawer.
The UFC system can connect almost anything to anything by purchasing the same basic filter housing and then simply choosing the necessary front and back plate of the UFC together with the spacer rings as required by the respective chip spacing. For this purpose, Baader offers a set with suitable UFC extension sleeves, as well as a S70 VariLock extension that is continuously adjustable from 15mm to 20mm, in order to keep the distance between the filter and image plane as short as possible. All components are optimized in order to get the largest possible passage in front of the actual filter drawer and still be able to precisely set the appropriate distance between telescope and chip. The filter drawer itself sits as close as possible in front of the camera, shadowing by the filter is minimized.