Allied International Home Security System ユーザーズマニュアル
AVT camera cleaning instructions
Hardware Installation Guide V2.0.0
22
Is it an impurity? – Identifying impurities
If you observe any image artefacts in your video preview of your AVT camera
you may have impurities either on the lens, filter/protection glass or, theo-
retically on the sensor protection glass, although every AVT camera gets
cleaned prior to sealing and shipment.
you may have impurities either on the lens, filter/protection glass or, theo-
retically on the sensor protection glass, although every AVT camera gets
cleaned prior to sealing and shipment.
Impurities (dust, particles or fluids) on the sensor or optical components
(
(
on page 22) will appear as a dark area, patch or spot on the image
and will remain fixed in the preview window while you rotate the camera over
the target.
the target.
Do not confuse this with a pixel defect which will appear as a distinct point.
It is crucial to differentiate between dust (e.g. flakes of skin, particles) and
other dirt (e.g. liquids, fingerprints, grease). Particles can either rest loosely
or can be more or less stuck to the optical surface.
It is crucial to differentiate between dust (e.g. flakes of skin, particles) and
other dirt (e.g. liquids, fingerprints, grease). Particles can either rest loosely
or can be more or less stuck to the optical surface.
Where is the impurity? – Locating impurities
Before you dismount the lens you should find out if the impurity is on the
filter, lens or sensor. Therefore you should view a uniform image (e.g. a white
sheet of paper) with the camera. The affected optical surface is identified
when a suspected optical component is moved and the dirt follows this move-
ment.
filter, lens or sensor. Therefore you should view a uniform image (e.g. a white
sheet of paper) with the camera. The affected optical surface is identified
when a suspected optical component is moved and the dirt follows this move-
ment.
1.
If you move only the lens (not the camera) and the impurity moves as
well, the impurity is on the lens.
well, the impurity is on the lens.
2.
If you move the IR cut filter/protection glass window and the impurity
moves as well:
moves as well:
Please carefully remove the filter/protection glass (for certain camera
models, indicated below, requiring a special tool which can be ordered
models, indicated below, requiring a special tool which can be ordered
Figure 3: Image with tiny dust on the filter (left) and dust on the sensor (right)