Baader Planetarium Fluorite Flatfield Converter Barlow.
The Fluorite Flatfield Converter was designed by a top German optical inventor to cover up to a 6x7cm format at magnifications up to 8x. The 4-element fluorite design provides a diffraction-limited, apochromatic flat field over a 90mm circular format. It produces a sharp, color-free image for any projection photography need. It can be coupled to 35mm cameras, 6x7 cameras (adapters are available for various camera models), as well as any CCD camera. The FFC also can be used visually for critical high-power lunar/planetary viewing. The fluorite lenses do not add any chromatic aberrations or other optical defects to the image. The lenses are corrected from deep violet to the IR regions, and present an excellent match to the new extended-wavelength CCD cameras.