Hi all,
I am currently working with the Arducam IMX296 Mono camera module on a Raspberry Pi (Bookworm OS / libcamera). I am trying to perform Lens Shading Correction (LSC) tuning for this specific module/lens combination.
The Issue:
I captured the calibration images using the following command (with a properly flattened JSON):While the resulting .jpg image looks completely normal, the generated Raw .dng file appears to be damaged or corrupted. Standard DNG viewers/editors fail to open it, or show incorrect data patterns.
Comparison:
I performed the exact same test using the Official Raspberry Pi IMX296 (Color) Global Shutter camera. Using the same command and environment, the DNG files generated by the official color sensor are perfect and valid. This issue seems specific to the Mono variant I am using.
Files for Reference:
JPEG: https://drive.google.com/file/d/1wdzGoN ... sp=sharing
DNG: https://drive.google.com/file/d/1EfI3uB ... sp=sharing
rpicam log: https://drive.google.com/file/d/1PcH9zQ ... sp=sharing
I would appreciate some advice on the following:
DNG Corruption: Is there a known issue with how rpicam-still or libcamera packs Raw data for Mono Global Shutter sensors that causes DNG corruption? Or does the Mono tuning file require specific parameters to generate a valid Raw file?
LSC on Mono Sensors: Is it necessary/recommended to perform the standard Lens Shading Correction (LSC) tuning process for a Monochrome sensor? (I understand color shading isn't an issue, but I assume luminance falloff/vignetting still needs correction).
System Info:
Platform: Raspberry Pi 4
Camera: Arducam IMX296 Mono
OS: Raspberry Pi OS Trixie (64-bit)
I am currently working with the Arducam IMX296 Mono camera module on a Raspberry Pi (Bookworm OS / libcamera). I am trying to perform Lens Shading Correction (LSC) tuning for this specific module/lens combination.
The Issue:
I captured the calibration images using the following command (with a properly flattened JSON):
Code:
rpicam-still -t 5000 --tuning-file ../uncalibrated.json -r -o imx296_4000k_1200l.jpgComparison:
I performed the exact same test using the Official Raspberry Pi IMX296 (Color) Global Shutter camera. Using the same command and environment, the DNG files generated by the official color sensor are perfect and valid. This issue seems specific to the Mono variant I am using.
Files for Reference:
JPEG: https://drive.google.com/file/d/1wdzGoN ... sp=sharing
DNG: https://drive.google.com/file/d/1EfI3uB ... sp=sharing
rpicam log: https://drive.google.com/file/d/1PcH9zQ ... sp=sharing
I would appreciate some advice on the following:
DNG Corruption: Is there a known issue with how rpicam-still or libcamera packs Raw data for Mono Global Shutter sensors that causes DNG corruption? Or does the Mono tuning file require specific parameters to generate a valid Raw file?
LSC on Mono Sensors: Is it necessary/recommended to perform the standard Lens Shading Correction (LSC) tuning process for a Monochrome sensor? (I understand color shading isn't an issue, but I assume luminance falloff/vignetting still needs correction).
System Info:
Platform: Raspberry Pi 4
Camera: Arducam IMX296 Mono
OS: Raspberry Pi OS Trixie (64-bit)
Statistics: Posted by DaPiLad — Wed Feb 11, 2026 10:10 am