Stereo camera calibration for large field of view digital image correlation using zoom lens

We propose a calibration method for stereo camera with a large field of view (FOV) using zoom lenses. We adopted Magill’s formula, using intrinsic parameters with small object distances to calculate intrinsic parameters with large object distances. We employed a regular sized calibration board to calibrate extrinsic parameters in the small FOV, using zoom lenses to reduce the FOV, and then calculated extrinsic parameters in the large FOV. Verification experiments showed 3D reconstruction error was approximately 1 mm when the FOV is about 6 × 6 m. The proposed calibration method will broaden the application range for 3D digital image correlation in scientific and engineering fields. •A large field-of-view dual-camera calibration method was presented.•Using Magill’s formula for distortion estimation at different object distances.•The field-of-view was reduced by zoom lens for extrinsic parameters calibration.•The proposed calibration method preserves the scale information well.