AOI Camera and Lighting System Guide

Published 31 July 2026Reviewed 17 September 2026Prepared and reviewed by SERVICEDIRECTORY

How this guide was prepared

SERVICEDIRECTORY reviewed the provider's published AOI explanation and organised the guidance around inspection objectives, defect size, sample coverage, optics and lighting, cycle time, false-reject control, programming, validation, and production integration.

Evidence boundary: SERVICEDIRECTORY did not independently validate a machine or production line. Detection capability, speed, repeatability, integration, and acceptance criteria should be demonstrated with representative samples and agreed test results. Read our editorial policy.

Why imaging design matters

An AOI camera and lighting system must create a repeatable image in which the required defect is clearly different from an acceptable product. Software cannot reliably recover information that the camera never captured. For this reason, imaging trials should begin with the defect, material, surface, geometry, and production movement rather than with camera resolution alone.

Glossy metal, dark plastic, transparent material, curved parts, fine print, shallow scratches, and mixed colours each interact with light differently. A lighting arrangement that works for one feature may hide another. Some systems therefore use several lights, exposure settings, camera angles, or imaging technologies to inspect different characteristics.

Camera and lens considerations

Field of view: the physical area included in one captured image.
Spatial resolution: the amount of image detail available across that area.
Working distance: the space required between the lens and product.
Depth of field: the height range that remains acceptably focused.
Exposure and motion: settings must control blur on moving products.
Lens distortion: measurement applications may require suitable optics and calibration.

A higher pixel count can provide more detail, but it may also increase processing and storage requirements. The correct design balances defect size, field of view, line speed, available space, and the number of images needed.

Common lighting approaches

Backlighting creates a strong silhouette and is useful for edges, gaps, profiles, or presence checks. Ring and directional lights reveal surface or shape information from selected angles. Diffuse illumination helps reduce harsh reflection on shiny or curved products. Coaxial lighting can provide even illumination along the camera axis for suitable flat surfaces. Ultraviolet, infrared, or short-wave infrared imaging may reveal material differences that are difficult to see under normal visible light, but suitability must be demonstrated with samples.

Lighting stability matters over time. Enclosures may be needed to block ambient light, while exposure monitoring, calibration, cleaning, and planned replacement help maintain results. Product fixtures should also control position and angle so that image changes represent the product rather than handling variation.

Preparing an imaging trial

Provide good samples, obvious defects, and borderline defects across expected colours, batches, finishes, and suppliers. State the smallest relevant defect and the required cycle time. During testing, inspect the image at production speed and under realistic vibration or movement. Evaluate repeatability over multiple samples instead of approving a single successful image.

Camera and lighting selection should be linked to software rules, handling, and validation. Review the broader AOI solution Malaysia guide before specifying individual components.