. Placed behind the target object
, and aimed directly back towards the sensor.
: Provides even, low-intensity illumination. Backlighting creates an image that shows a dark shadow of the part (a silhouette) which can be inspected for proper size or shape
It is the highest contrast
of any technique, and therefore the most accurate. Backlighting highlights differences in translucency
The best candidate for backlighting is a part that can be separated from its background.
Translucent: Term used to describe materials that have the property of reflecting a part and transmitting a part of incident radiation.