Technical Guides
Choose substrates and coatings, prepare DWG drawings and define measurable pattern and inspection requirements.
Dot Array or Checkerboard: Choosing a Camera Calibration Target
Compare feature geometry, software conventions, target size and validation before choosing a planar camera calibration pattern.
Pattern Polarity, Film Side and Viewing Direction
Define clear and opaque regions, illumination mode and the required reading side without confusing a film opening with a hole through glass.
Siemens Star Testing: Focus, Frequency and Image Interpretation
Convert radius to spatial frequency, distinguish genuine detail from artefacts and choose the analysis method for binary or sinusoidal stars.
NBS 1952 Testing: Frequency, Magnification and False Resolution
Read three-bar groups correctly, convert target frequency to image frequency and distinguish a visual limit from contrast-transfer measurements.
NBS 1963A Infinity-Conjugate Testing
Use five-bar targets with a collimator, convert physical chart frequency into angular resolution and avoid conjugate, sampling and false-resolution errors.
Checkerboard Camera Calibration: Corners, Capture and Validation
Set corner counts and units correctly, capture useful poses and validate camera calibration beyond a single reprojection-error value.
Dot-Array Camera Calibration: Geometry, Detection and Validation
Define circle-grid coordinates, match OpenCV or HALCON settings and assess sampling, perspective centre bias and measurement accuracy.
Concentric-Square Targets: Scale, Centre and Distortion Checks
Set a reproducible µm-per-pixel scale, inspect centring and separate perspective from lens distortion with nested square references.
Optical Reticle Selection, Installation and Parallax
Choose the pattern by function, place it at the correct focal plane and verify scale, orientation, illumination and parallax in the complete instrument.
Reticle Focal Planes, Parallax and Optical Alignment
Understand where a reticle sits, how the observer sees it with the target and how focal-plane and alignment errors enter the instrument.