Takahashi CCA-250 Corrected Cassegrain Astrograph
Introduced in 1998, the BRC-250 astrograph adopted a totally original optical design, based on Baker-Ritchey-Chrétien, perfectly designed for the imagery at that time. Following the recent evolution of CCD cameras offering larger sensors, Takahashi decided to modify its optical design. To work out this new CCA-250, successor of the BRC-250, the optician engineer Mr Mori Hitoshi opted for a Cassegrain base to lead to this new instrument perfectly adapted for the various objects of the deep sky.
CCA-250 (CCA stands for Corrected Cassegrain Astrograph) offers 3 kinds of focal lengths by the addition of optional reducers and extenders. From F/5 standard focal ratio at primary focus, it is possible to go to F/3.6 by using one of the 2 reducers or to go to F/7.5 by using one of the 2 extenders available. The choice of the model of reducer and extender will depend on the image circle needed, but also according of the size of the sensor of the camera used.
Finally Takahashi carried out a very multi-purpose astrograph offering a extremely high standard product bringing a great optical quality as well as irreproachable mechanics on top of which is added a splendid design associating aluminum and carbon.