The Baader FCCT-II from Alpine Astronomical was designed exclusively for Celestron's RASA 8 Astrograph with 90mm QHY 268 / 294 cameras. It is a filter changer with camera adjustment mechanism for covering the largest possible field size that the RASA8 can supply, enabling sharp image corners and ultimately fast fine corrections to the optical plane. The Baader FCCT allows quick filter exchange as well as very easy correction of any existing tilt?without having to remove the camera from the RASA 8" each time.





Celestron's most transportable astrograph, the RASA (Rowe-Ackermann Schmidt Astrograph) 8" can capture spectacular deep-sky wide-angle images in seconds. This incredibly fast f/2.0 system is the perfect telescope for modern astronomical CMOS color cameras, smaller CCD cameras, and mirrorless cameras. What would otherwise require several nights of exposure time can be accomplished with the RASA in a single night, in principle. Until now, the most severe obstacle was to get the stars in each corner of the chip really round and minimized in size. To do this, the camera had to be removed in order to reach the adjustment screws in the front of the Schmidt plate. But whenever the camera is put back in place, this will unavoidably result in a small lateral offset of the mechanical image train, which causes another corner of the image to show slightly distorted stars. This problem is solved by using the FCCT, since nothing needs to be disassembled anymore.





The RASA 8's image plane is so close to the Schmidt plate that the original front adjustment screws cannot be reached once a camera is connected. To remedy this shortcoming, the FCCT can accommodate specially designed, 3D-printed thin filter drawers and, in addition, precisely align the chip plane within fractions of a millimeter by means of easily accessible adjustment screws positioned 120° apart at the side of the filter chamber.