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The BRC-250 employs non-spherical surfaces for both the primary and secondary mirrors, and when they are combined with two supplementary lenses, elimates spherical aberration, coma, and even astigmatism with a flat field. It produces a focal ratio of f/5 with a 100mm 5 degree diameter image circle. It also produces an amazing 2 micron stellar image at the center of the field.
The BRC-250 employs the Baker method to flatten the field over a wide field. However, because its primary and secondary mirrors are hyperbolic, production was difficult. today, Takahashi's unique technique in polishing non-spherical surfaces enable the first mass production of Baker Richie Chretiens.
The large 100mm diameter image makes the BRC-250 a versatile astrograph. The following formats can be used: 35mm, 6x7, 6x9, and 4x5. The BRC-250 is temperature compensated by using a space age state-of-the-art carbon fiber tube which assures precise focus that will not change with temperature fluctuations.
The extremely small stellar images makes the BRC-250 the perfect instrument for CCD imaging. The 100mm diameter image circle will accomodate the largest commercially available CCD cameras.