OV2311 dark frames show reverse vignetting / reverse lens shading in low/zero light

  1. Where did you get the camera module(s)?

  2. Model number of the product(s)?
    SKU B0322, OV2311 UVC USB Arducam camera

  3. What hardware/platform were you working on?
    Windows 10, USB UVC

  4. Instructions you have followed. (link/manual/etc.)
    Quick Start - Arducam UVC Cameras on Windows - Arducam

  5. Problems you were having?

I’m having trouble getting the camera to be very effective in low light because of this pattern, a gradient that looks like the opposite of lens shading. With the camera shielded from all light, it shows this pattern basically identically with any exposure length, and it’s not affected by running lower fps or attaching a heatsink to the back of the sensor. It does however change slightly as light is let in and the scene brightness changes, so I’ve been unable to calibrate it away. Increasing gain increases the brightness of the whole image including the gradient. I’m trying to use this sensor on a 200mm lens for star detection and tracking, and the gradient and banding are making the software struggle to differentiate that from the gradients of the stars themselves.

  1. The dmesg log from your hardware?
    (not on linux)

  2. Troubleshooting attempts you’ve made?
    I’ve tried 4 different UVC camera control apps and they all show the same behavior: Amcap, Sharpcap, PHD2, and the Windows camera app. Different apps have different amounts of success controlling the camera, but the gradient appears the same on all of them.

  3. What help do you need help with?
    How can I get rid of this gradient? What is it?


Welcome to our community. It does due to the lens shading fix mode. Using circle mode, it will exist this phenomenon. Don’t worry and I will try to tuning it again. When I have fixed this issue. I will tell you how to
update the firmware.
Let me know if you need more help.