Microscan Visionscape FrontRunner, Руководство пользователя

Страница: 131 / 152

Illuminating the Part
Creating a Good
Image
A
v4.1.3, April 2012 Visionscape FrontRunner™ User’s Manual A-5
to follow; however, the following basic lighting concepts, combined with
some experimentation, will help you create good lighting.
Note: Always use task lighting designed for your application and shield
the part from ambient light.
Lighting Considerations
When lighting a part for vision analysis, you should consider the following
features in selecting a lighting scheme:
• Surface Characteristics — Surface characteristics, as they relate to
light, is a critical element when selecting the correct lighting type. You
must consider the type of surface, and its color, before purchasing
your illumination style:
– Textured
– Reflective
– Diffuse
– Absorptive
• Geometry — The geometry may determine the direction of the
illumination. Will the complete item require illumination?
• Size — The size of the part will determine the size of the light.
• Region of Interest (ROI) — How will the ROI compare to the rest of
the part?
Types of Lighting
With advances in lighting, selecting an appropriate illumination type can
be confusing. Basic and Advanced Illumination types will be discussed
and their basic influences explained. Diffused, Point-source lighting and
polarizers also influence lighting. Also, the placement of the light source
will affect your decision on lighting types. For difficult lighting applications,
we recommend you contact Microscan NERLITE (www.nerlite.com).
• Basic Illumination