Photon Focus Luxima DR4-D1280-L01-FB, User Manual, Page: 75 / 151

12.3 Column FPN Correction
12.2.3 Storing the calibration in permanent memory
After running the calibration procedure (see Section 12.2.2) the calibration values are stored in
RAM. When the camera is turned off, their values are lost.
To prevent this, the calibration values must be stored in flash memory. This can be done by
clicking on the property
BadPixelCorrection_SaveToFlash
(in category
BadPixelCorrection
). Wait
until the command has been finished.
Storing the calibration in permanent memory overwrites the factory calibration.
12.3 Column FPN Correction
Due to the readout structure of the image sensors there is a column-wise fixed pattern noise
(FPN). The Column FPN Correction (ColCorrection) adds or subtracts a fixed value to a column.
These values are obtained by a calibration process. The ColCorrection of the camera was
calibrated at Photonfocus production facility.
12.3.1 Enable / Disable the Column FPN Correction
The Column FPN Correction can be enabled or disabled with the property ColCorrection_Enable
(in category Photonfocus / ColCorrection ). By default the correction is enabled.
12.3.2 Calibration of the Column FPN Correction
The Column FPN Correction of the camera is correctly calibrated at Photonfocus production
facility. Although a new calibration is normally not required, you can recalibrate the Column
FPN Correction with the following instructions:
1. Setup the camera to the mode where it will be usually used. (Exposure time, ...). The
width and height should be set to its maximal value.
If different exposure times will be used, calibrate the camera under the longest
exposure time.
2. Start the aqcuisition of the camera.
3. Close the lens of the camera or put a cap on the lens. The calibration requires an uniform
dark image. The black level offset should be set so that all pixels (except defect pixels)
have values above 0.
4. Run the command
ColCorrection_CalibrateBlack
(category
ColCorrection
) by clicking on
the corresponding button.
The calibration process is waiting now for at least one image. If the camera is in
triggered mode, the user must apply the corresponding trigger.
To get the best calibration results, the camera should have achieved the working
temperatur.
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