Cleaning optical components
72
Prosilica GC Technical Manual V2.2.0
Identifying impurities
If you observe any image artifacts in your video preview of your Prosilica GC
camera you may have impurities either on the lens, filter/protection glass, or on
the sensor protection glass. Every Prosilica GC camera is cleaned prior to sealing
and shipment; however, impurities may develop due to handling or unclean
environments.
As shown in figure
31
, impurities (dust, particles or fluids) on the sensor or optical
components appear as a dark area, patch or spot on the image and remain fixed in
the preview window while you rotate the camera over the target.
Do not confuse this with a pixel defect which appears as a distinct point. Particles
can either rest loosely or can be more or less stuck to the optical surface.
Locating impurities
Before you dismount the lens you should find out if the impurity is on the filter,
lens, or sensor.
1.
Start acquiring a uniform image (e.g., a white sheet of paper) with the camera.
2.
To identify the affected surface, move the suspected optical component and
see if the contamination follows this movement.
a.
If you move only the lens (not the camera) and the impurity moves as
well, the impurity is on the lens.
b.
If you move the IR cut filter/protection glass window and the impurity
moves as well, the impurity is on the filter/protection glass. Carefully
remove the filter/protection glass and clean it on both sides using the
techniques explained in the next section. If the impurity is neither on the
lens nor the IR cut filter/protection glass, it is probably on the sensor.
Figure 31:
Image with tiny dust on the filter (left) and dust on the sensor (right)
Removing IR cut filter
A pin spanner wrench (Allied Vision order code: E9020001) suitable for IR filter
removal is available for purchase from Allied Vision for all Prosilica GC cameras.
