Which machine-vision light do I need?
Lighting decides most of what the camera can see. Start from the part and the defect, then pick the geometry. If two answers fit, test both - we can help with a short setup on your part.
Measure an outline, holes or a gap
Put a backlight behind the part for a black silhouette on white. For thick parts or high accuracy use a collimated backlight, or a collimated spot light with a telecentric lens.
Shiny flat surface
Glare and hot spots? Use a coaxial light: it lights along the camera axis so flat mirror-like areas appear evenly bright and defects show dark.
Shiny curved or crinkled part
Use a dome light or a shadowless light: diffuse light from every angle removes reflections.
Engraving, embossing, scratches, edges
Use a low-angle ring or bar light so light grazes the surface; raised and cut features throw shadows the camera can see. See ring lights and bar lights.
General presence, print and color checks
A high-angle ring light around the lens, or two bar lights, give bright even light for most matte parts.
Moving web, sheet or conveyor
Line-scan cameras need a bright narrow line: line scan lights, fan or water cooled for long duty and high speed.
Colour
Match the light colour to the part to raise contrast: a colour looks bright under light of the same colour and dark under its opposite. Red penetrates many plastics and suits general work; blue shows fine surface detail; white is for colour cameras and colour checks; infrared ignores most printed colour.
Controller
Every light here runs on 24 V DC (a few high-power models on 48 V). A light controller sets brightness per channel and strobes the light from the camera trigger, which allows overdrive and freezes motion.
Lens
Pick the sensor format first, then the focal length for your field of view and working distance. For measurement use a telecentric lens; for line-scan cameras use a line-scan lens matched to the sensor (4K, 8K, 16K). See lenses.