GEAR IMPROVEMENT by Chris Schur Correcting a Tilted Sensor Here's how you can get perfect stars across your camera's entire field of view. A stronomy cameras with large CMOS detectors are very popular these days. Such cameras have higher sensitivities and lower noise characteristics than their CCD predecessors and cost less, too. Astrophotographers pairing them with fast Newtonians, apochromatic refractors, or camera lenses are producing the deepest astronomical images ever. However, many imagers soon discover that shooting with a large detector comes with its own set of challenges. High on that list is a tilted sensor causing focus variation and distorted stars across the image frame. Fortunately, nearly all astronomy cameras with an APS-C or larger sensor include an adjustable tilt plate on the front of the camera to compensate for this. Correcting the tilt using the manufacturer's procedure can be a daunting and frustrating experience often doomed to failure. Here's a method I developed to diagnose and fix sensor tilt indoors. It requires a simple testing rig made using common hand tools to achieve the sharpest deep-sky images your equipment is capable of producing. uPERFECT STARS After removing the tilt of the author's camera sensor using the rig he devised, this portrait of the emission nebula IC 1396 displays sharp stars right to the corners of the field. Retaining clamps Sensor target Camera mount Masonite plate Laser Base plate Leveling screws 62 APRIL 2025 * SKY & TELESCOPE