Baader FCCT II for RASA 8", suitable for QHY cameras with 90 mm diameter

Baader FCCT II for RASA 8", suitable for QHY cameras with 90 mm diameter

The Baader FCCT was designed exclusively for Celestron´s RASA 8 Astrograph and QHY cameras. It is a filter changer with camera adjustment mechanism for covering the largest possible field size that the RASA8 can suppply, enabling sharp image corners and ultimately fast fine corrections to the optical plane. The Baader FCCT (Filter Changer Camera Tilter) allows quick filter exchange as well as very easy correction of field any existing tilt - without having to remove the camera from the RASA 8" each time.

Celestron´s most transportable astrograph, the RASA 8" Rowe-Ackermann Schmidt Astrograph, 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 system 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, unavoidably this will 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.

But the RASA 8 has the image plane so close to the Schmidt plate that the original front adjustment screws cannot be reached as soon as a camera is connected. To remedy this shortcoming, the FCCT II 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. This makes working with the RASA 8 a pleasure, without having to fight for a perfect image position for a long time.

Suitable filters
For the FCCT II, Baader offers three sizes of 3D-printed filter drawers that exclusively accommodate unmounted filters with diameters of 31 mm / 36 mm and 2" (unmounted diameter = 47.4 mm). Smaller filters than 31 mm very often lead to vignetting in the image corners even with small chip sizes and force cropping of the image content - leading to correspondingly unhappy customers. For this reason Baader does not offer the smallest possible filter size of (unmounted) 1.25" filters for the RASA 8". The large angle of view of 14 degrees forces to choose filters as large as possible to avoid image deterioration at the corners as well as vignetting and reflections. A filter should at minimum be 20% larger in diameter than the chip diagonal.

Instructions

The manufacturer provides instructions, you can download the PDF here.

Safety informations: PDF Download