Machine Vision & Industrial Inspection AI calculator
Minimum Detectable Defect Size Calculator
A camera can only reliably detect a defect if the defect covers enough pixels to distinguish it from background noise and part texture. In practice, a minimum of 2 to 3 pixels across the defect is required for reliable detection, and 5 or more pixels is preferred for reliable classification by type. Enter the horizontal field of view, the camera horizontal pixel count, and the minimum pixels required for your detection method. The result shows the minimum detectable defect size in mm. Compare this to the smallest defect in your inspection specification.
What this calculator does
- Calculate the minimum defect size a machine vision camera can reliably detect by multiplying the inspection resolution (mm per pixel) by the minimum number of pixels required to detect and classify a defect.
- Use it when writing or validating a machine vision specification to confirm that the camera and lens combination can detect the smallest defect in the inspection requirement.
- Turns horizontal field of view (fov width), camera horizontal pixel count, minimum pixels required to detect a defect into a ratio for min detectable defect in machine vision and industrial inspection ai.
Formula used
- Inspection resolution = FOV width / horizontal pixel count
- Minimum detectable defect size = inspection resolution x minimum pixels required
- Example: (220 mm / 2448 pixels) x 3 = 0.27 mm minimum defect size
Inputs explained
- Horizontal field of view (FOV width): Enter the horizontal FOV in mm. Use the Field of View calculator to find this from sensor width, focal length, and working distance.
- Camera horizontal pixel count: Enter the horizontal pixel count from the camera specification. Higher pixel count improves resolution and reduces minimum detectable defect size.
- Minimum pixels required to detect a defect: Enter the minimum number of pixels that must span the defect for reliable detection. Use 2 for threshold go-no-go detection, 3 to 5 for reliable detection, and 5 to 8 for defect type classification.
How to use the result
- Use it when min detectable defect in machine vision and industrial inspection ai is being normalized for comparison.
- Ratios hide absolute change; pair with the underlying counts when you present.
Common questions
- Why use this min detectable defect tool for machine vision and industrial inspection ai? Calculate the minimum defect size a machine vision camera can reliably detect by multiplying the inspection resolution (mm per pixel) by the minimum number of pixels required to detect and classify a defect. You get a ratio you can defend before quoting, scheduling, or sign-off.
- What numbers should I focus on first? horizontal field of view (fov width), camera horizontal pixel count, minimum pixels required to detect a defect usually move the ratio most. Pull from measured machine vision and industrial inspection ai runs, supplier data, and recent quotes rather than memory.
- How should I use the result? Use the ratio in machine vision and industrial inspection ai reporting or as a normalized score against another period.
- What should I verify first? Confirm both inputs are from the same time window and scope before you trust the ratio.
Last reviewed 2026-05-12.