filters / accessories resource guide
illumination cameras liquid lens / specialty telecentric fixed focal length
microscopy /
objectives
DIRECTIONAL ILLUMINATION
Point source illumination from single or multiple sources. Lenses can be used to focus or
spread out illumination. Left image also uses a polarizing filter to reduce glare.
PROS
• Bright
• Flexible
• Adaptable
• Uniform
GLANCING ILLUMINATION
Point source illumination similar to directional illumination, except at a sharp angle of incidence.
PROS
• Show Surface
Structure
• Enhances Object
Topography
CONS
• Shadowing
• Glare
CONS
• Hot Spots
• Extreme
Shadowing
DIFFUSE ILLUMINATION
Directional illumination in-line with the optics. Lens looks through circular aperture in center
of illuminator or light guide.
156 +44(0) 1904 788600 | Edmund Optics® targets Common Illumination Types for
Opaque Objects (like our Target)
Section 11.2:
Common Illumination Types
The various examples below illustrate the different types of illumination
that are common in machine vision applications. Because
the samples that are imaged can vary in shape, material, and reflectivity,
the target used throughout this section was developed to
demonstrate the strengths and weaknesses of these various lighting
schemes for a variety of object features. The grooves, colors,
surface deformations, and specular areas on the target represent
some of the common trouble areas that may demand special attention
in actual applications.
PROS
• Reduces Glare
• Provides Even
Illumination
CONS
• Large
• Difficult to Fit in
Confined Spaces
• Surface Features
Less Distinct
PRODUCTS
USED
• Fiber Optic Light
Guides
• Focusing Assemblies
• LED Spot Lights
PRODUCTS
USED
• Fiber Optic Light
Guides
• Focusing Assemblies
• LED Spot Lights
PRODUCTS
USED
• Diffuselite LED
Illuminator
• LED Linear Lights
APPLICATION
Inspection and measurement
of matte
and flat objects.
APPLICATION
Identifying defects in
an object with depth
and examining finish
of opaque objects.
APPLICATION
Best for imaging
large, shiny objects
with large working
distances.
Diffuse even light from an extended source.
Lighting Geometry Selection Guide:
Application Requirement Object Under Inspection Suggested Type of Illumination
Reduction of Specularity Shiny Object Diffuse Front, Diffuse Axial, Polarizing
Even Illumination of Object Any Type of Object Diffuse Front, Diffuse Axial, Ring Light
Highlight Surface Defects or Topology Nearly Flat (2-D) Object Single Directional, Structured Light
Highlight Texture of Object With Shadows Any Type of Object Directional, Structured Light
Reduce Shadows Object With Protrusions, 3-D Object Diffuse Front, Diffuse Axial, Ring Light
Highlight Defects Within Object Transparent Object Darkfield
Silhouetting Object Any Type of Object Backlighting
3-D Shape Profiling of Object Object With Protrusions, 3-D Object Structured Light
PROS
• Reduces Shadows
• Relatively Even
Illumination
CONS
• Circular Glare
Pattern
from Highly
Reflective Surface
• Difficult to Mount
PRODUCTS
USED
• Fiber Optic Ring
Light Guides
• LED Ring Lights
APPLICATION
Wide variety of
inspection and measurement
systems
with matte objects.
RING LIGHT