140
•
Additional Reference Information
Linea2 5GigE Series Camera
Optical Considerations
This section provides an overview to illumination, light sources, filters, lens modeling, and lens
magnification. Each of these components contribute to the successful design of an imaging
solution.
Illumination
The wavelengths and intensity of light required to capture useful images vary per application. The
image will be affected by speed, spectral characteristics, exposure time, light source
characteristics, environmental and acquisition system specifics, etc. Teledyne DALSA
’s
Web Site
introduces this potentially complicated issue. Browse the Knowledge Center and the White Papers
and Technology Primers sections.
Exposure settings have more effect than illumination. The total amount of energy (which is related
to the total number of photons reaching the sensor) is more important than the rate at which it
arrives.
Example:
5
J/cm
2
can be achieved by exposing 5 mW/cm
2
for 1 ms, or 5 W/cm
2
for 1
s.
Light Sources
Keep these guidelines in mind when selecting and setting up a light source:
•
LED light sources are inexpensive and provide a uniform field with a longer life span compared
to other light sources.
•
Halogen and fiber-optic light sources provide very little blue relative to IR.
•
Some light sources age and produce less illumination in some areas of the spectrum.
