Altair PlanoStar 2" 1.0x Flattener for 80mm F6 Triplet APO

This field flattener is designed to work with the Altair Astro Starwave 80mm F6 ED Triplet APO. It has an M48 rear thread adaptor for connecting your DSLR or CCD camera. All triplet refractor lens systems with good colour correction exhibit some natural field curvature which, while not relevant for visual observation, can be visible in astro-images. This field flattener screws directly into the rear focuser rotator, converting it into an astrograph with a flatter photographic field than a triplet lens system alone. It does not change the focal length of the telescope significantly enough to affect subject framing. Altair PlanoStar v2 Field Flattener specification: The ideal distance to CCD sensor from the rear of the rear shoulder (excluding the protruding M48 thread) is 55mm. Tests indicate that the flattener is tolerant about 1.0mm either side of this distance. The smaller your CCD chip, the less critical spacing becomes. The flattener is threaded directly to the rear of the focuser