RCOS 100mm Series - Field Flattener/Corrector (FFC-100mm)...
Designed specific to the RCOS 20RC.
Designed exclusively for RC Optical Systems, this large (4 inch aperture) Field Flattener/Corrector reduces field curvature and off axis astigmatism, while also reducing off-axis spot size. The FFC-100mm mounts on the Back Plate or inside the 100mm PIR. There is no telecompression and will allow the optics to operate at their native f/ratio.