Skip to main content

ABOUT NOCTVISION

Recording, in numbers, where optics, lighting, and hardware get entangled

NOCTVISION is a technical record site covering machine vision and edge AI. This site organizes the problems encountered when building vision systems in industrial settings — the points where optics, lighting, and hardware are entangled in ways that algorithms alone can’t resolve.

Written by an engineer who has handled mechanical design and project management for production equipment since 2005

New here? Start Here More about this site

Three principles

  1. Optics Is PhysicsThe first step in system design is the lens and the lighting. This site covers physical quantities and formulas that can be verified — focal length, aperture value, depth of field.
  2. Only Verified MaterialCode that hasn’t been confirmed to work isn’t posted. Code includes comments on the core logic and the related physical formulas so a reader can reproduce it.
  3. Edge Environments Are the BaselineThe standard is what actually runs on an edge board, not the ample resources of a PC. Results are presented as numbers — processing speed, inspection resolution, accuracy.

Browse by topic

  • OPTICS41 posts

    Optics

    This section covers the values that are settled by calculation first: the size of one pixel on the object, working distance (WD) and depth of field. How many pixels a defect occupies on screen is decided by these numbers before any algorithm runs.Start with theseHow to Calculate Machine-Vision Lens Focal Length — the basic formula from FOV, WD and sensor sizeMachine Vision Lens Calculator — where the shortcut formula breaks at higher magnification, plus depth of field and diffractionVision Types Split First by Wavelength and Pixel Size — several vision methods compared in one tableIn SWIR, One Stop Down Erases a 3.4 µm Pixel — how diffraction covers a pixel as wavelength growsUnfamiliar terms are explained in the Glossary, and a reading order across topics is in the Start Here guide.

    Start hereHow to Calculate Machine-Vision Lens Focal Length

  • LIGHTING29 posts

    Lighting Design

    With the same camera, a defect can appear or vanish depending on the angle and wavelength of the light. This section collects articles on choosing among coaxial, dome, dark-field and backlight methods, and on handling reflection, wavelength and brightness drift.Start with theseSix Machine-Vision Lighting Methods and How to Choose — how each method works and the order for choosingFor Scratches on Highly Reflective Metal, Choose the Lighting First — a lighting map by surface typeWhy a Black Spot Remains in the Center of a Dome Light — the viewing-hole dark spot and fill lightWhen the Light Dims by 5 %, How Many Good Pixels Turn Into Defects? — how brightness change affects decisionsUnfamiliar terms are explained in the Glossary, and a reading order across topics is in the Start Here guide.

    Start hereSix Machine-Vision Lighting Methods and How to Choose

  • ALGORITHM39 posts

    Vision Algorithm

    This section covers the rules and models that pick defects out of an image, and the cost when a decision is wrong: how rule-based and deep-learning methods share the work, anomaly detection, and filter order. It is the stage that turns the image made by lighting and optics into a pass/fail decision.Start with theseDeep Learning vs. Rule-Based Algorithms, When to Use Which — the conditions that favor eachOverdetection or Missed Detection, Which One Costs More? — setting the decision line by costBuilding a Vision Inspection App with PySide6 and OpenCV — full code for a minimal UI that tunes parameters on screenMust Every Normal Patch Be Remembered? — coreset design for memory-bank anomaly detectionUnfamiliar terms are explained in the Glossary, and a reading order across topics is in the Start Here guide.

    Start hereDeep Learning vs. Rule-Based Algorithms, When to Use Which

  • EDGE AI22 posts

    Edge AI

    This section covers what goes wrong when an inspection model runs on a small board next to the machine instead of a server: accuracy lost to quantization, latency added by heat, and throughput set by the camera interface. These are items to confirm with numbers on site.Start with theseFour Snags in Initial Jetson Orin Nano Setup — a check order for first power-onIt Worked on the Server, So Why Does Accuracy Drop on the Edge? — the order for finding accuracy lossIs It Safe When the Average Latency Fits? — splitting the latency budget by p99Why Edge AI Vision Fails on the Factory Floor — a troubleshooting map from symptom to causeUnfamiliar terms are explained in the Glossary, and a reading order across topics is in the Start Here guide.

    Start hereIt Worked on the Server, So Why Does Accuracy Drop on the Edge?

Latest posts