The BRC-250 uses aspherical surfaces for both the primary and secondary mirrors, and when they are combined with two supplementary lenses, eliminates spherical aberration, coma & astigmatism with a flat field. It gives a focal ratio of f/5 with a 100mm 5° image circle. It produces an amazing 2 micron stellar image at the center of the field. Thus making the BRC-250 the perfect instrument for CCD imaging. The 100mm diameter image circle will accomodate the largest commercially available CCD cameras.

Thanks to 100 image circle, from 35mm to 4x5" format film can be covered. 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 BRC-250 employs the Baker method to flatten the entire field of view. However, because its primary and secondary mirrors are hyperbolic, production was difficult. Today, Takahashi's unique technique in polishing non-spherical surfaces enables the first mass production of Baker Ritchey Chretien

Specification:
Primary mirror: 260mm Hyperbolic with enhanced coatings
Secondary mirror: 120.5mm Hyperbolic with enhanced coatings
Focal length: 1268mm
Image circle: 100mm/5°
Main tube: diameter of 280mm (11.02"), length 595mm (23.42") weight 15.6kg (34.32lbs)
Finder: 7x50, 6.3° field of view; with illuminator. 11x70, 4.2° finder is optional
Tube Material: Aluminum
Film formats usable: from 35mm all the way up to 4x5"
Focal Length: 1268mm
High reflectance aluminum protected coating
Obstruction: 0.49
Corrector: 2 lenses all surfaces multicoated
Image circle diameter illuminated on film: 100mm, 60% without vignetting
Photo resolution: 2 micron near centre; 10 micron at the outer edge
Field maximum: 4.5° on film format 4X5"
Tube weight: 15.6kg