Optics
Lens selection, focal length and depth of field, F-number, aberration correction — the fundamentals and calculations of machine vision optics.
-
There Are Defects That Vanish in Visible Light — Inspection Design Beyond the 1 μm Barrier in SWIR Imaging
A defect with no contrast in visible light must be seen by changing the wavelength. This article maps how SWIR imaging works, how Cu-Cu bonded sensors opened up pixel pitch, and how lighting…
-
Catching 20 μm Sink Marks in High-Gloss Injection-Molded Parts with Phase Measuring Deflectometry (PMD) — The Last Gap Polarization Fusion Fills
A shallow depression on a specular surface creates almost no contrast under diffuse illumination. This article maps how PMD turns slope into the measurand, and how polarization fusion resolves the ambiguity a single…
-
Where the μm Step Disappears: Measuring Both-Side Thickness Simultaneously with a Two-Channel Chromatic Confocal Controller
A 2 μm coating deviation is invisible to a 2D vision camera because neither color nor shape changes. This article covers how chromatic confocal converts axial displacement into a spectral signal, and how…
-
Liquid Lens Autofocus: Solving the Focus Problem on High-Mix, Low-Volume Production Lines
Focus subtly drifting every time a lot changes is a familiar problem on PCB and injection-molded part lines. Electrowetting liquid lenses cut refocus time to within tens of ms, but they are not…
-
Ultra-High-Speed Micro-Defects Caught by Event Cameras (Neuromorphic Vision) — Seeing What Frames Miss
A wobbling connector pin, a flicking solder ball, a vibration-shifted alignment — these moments pass between frames on an ordinary camera. Event cameras (DVS) capture only brightness changes, at microsecond resolution.
-
What 2D Contrast Can’t See: How 3D Structured-Light Inspection Measures Solder Joint Height
Two connector leads that look nearly identical in a 2D image can differ entirely in height. 3D structured-light inspection reconstructs actual surface shape instead of relying on contrast, but specular materials like solder…
-
When Specular and Matte Meet in One Frame: Reviving Contrast with HDR Multi-Exposure Fusion
When a specular connector and a matte resist surface share one FOV, a single exposure can't capture both. Here is how HDR multi-exposure fusion recovers contrast on mixed-reflectivity surfaces, and when cross-polarization is…
-
Specular Reflection Erases Defects: How Cross-Polarization Catches Missed Detections on Highly Reflective Surfaces
When a plated connector and a matte housing share a FOV, specular reflection saturates the highlight and buries defects. Here is how cross-polarization filtering physically blocks specular reflection, and when it is favorable…
-
The Tug-of-War Between Distortion Correction and Depth of Field: How Telecentric Lenses Catch Micro-Defects Without Losing Them
Raise lens magnification to resolve a micro-defect and depth of field narrows; layer distortion on top and dimensional measurements start to drift. A look at how magnification, DOF, distortion, and reflectivity interact in…
-
Why the PoE Network Card Sets the Limit on Your Optical Setup in a Multi-Camera Inspection Line
Scale a PCB line from one camera to four or eight and the first bottleneck is cabling, not the lens. How a PoE network card's power and bandwidth budget has to be designed…
