Customized Shading Correction - JAI CV-M 9CL Operation Manual

6.5.1. Customized shading correction.

From factory, the CV-M9CL camera is delivered with a shading correction adjusted to work with
homogeny lightening coming from a DC regulated halogen lamp at 3200K and a certain Fujinon
lens. This shading data stored in the factory area is also used for the 3 user areas. For other
fixed illumination and for another fixed lens in a specific setup, it makes sense to make a
temporary customized shading calibration.
When such calibration is done, it will be used in the camera until next power up. Here the old
factory shading data will be called and used.
With the Camera Control Tool it is possible to store the customized shading corrections in a file.
This file can then be loaded into the camera after next power up.
To make a customized shading calibration it is most important to avoid flickering of the
lightening like AC powered light and also reflections should be avoided – such effects will
interfere with the calibration. Apart from that the light temperature and the light density over
the area of interest should be exactly as for the real setup.
The camera setting has to be as follows:
•
Master gain 0dB
•
Individual gain 0dB
•
Shutter off
•
Trigger modes off - use Normal mode
•
Binning and Partial scan off
•
Use 10 bit output mode
•
Shading corrector off
Continue with the following:
•
Set up the illumination, as it should be in the real application.
•
Place a perfectly flat white object (piece of paper) at the actual scene. No reflections
must be visible.
•
Adjust the lens iris and focus to the level, which should be used in the real application.
•
Make sure that the signal level at scene centre equals around 800LSB.
•
When the above is okay then perform an Auto White Balance [command: WB=1].
•
Be sure that no part of the image is saturated.
•
Now the camera is ready to perform an Auto Shading Correction: [Command: ATSH=0].
•
If the shading correction is successful, the camera will respond COMPLETE.
•
Turn the shading on and off some times to verify the effect of the shading correction.
[Command: SDM=1 and SDM=0].
•
The new customized shading corrections data will be used for all user areas until factory
area is called, or until next power up, where the factory shading corrections are called.
•
With the camera control tool (version 1.2 or later), the customized shading data can be
stored in a file. For later use, this file can then be loaded into the camera.
CV-M9 CL
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