Greenish images after setting custom exposure time

Raspberry Pi Cameras
1

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

  2. Model number of the product(s)?
    IMX467

  3. What hardware/platform were you working on?
    RPI 4

  4. Instructions you have followed. (link/manual/etc.)

  5. Problems you were having?
    Color balance is too green

  6. The dmesg log from your hardware?

  7. Troubleshooting attempts you’ve made?

  8. What help do you need?

I have a small program like following, and get very greenish images after deactivate auto exposure and setting my own exposure time in low light room. How can I set my own exposure and keep a correct white balance ? Thanks for your help

from picamera2 import Picamera2, Preview
import time
 
picam2 = Picamera2()
picam2.start_preview(Preview.QT)

 
preview_config = picam2.create_preview_configuration()
picam2.configure(preview_config)
picam2.start()
time.sleep(1)
picam2.controls.AeEnable = 0
picam2.controls.AwbEnable = 0
picam2.controls.ExposureTime = 5000000
picam2.controls.AnalogueGain = 750

time.sleep(10)


picam2.stop()
2

@watchever

I would advise against turning off AWB. Disabling it may make it difficult to adjust the effect to your liking

3

Thanks Edward, well the issue is quite the same with awb disable or not. If I comment the line with AwbEnable I have same greenish image.
When autoexposure is diable and set exposure to high value, I have first a good image with natural colors but then it becomes darker and more and more green. Like there was new automatic adjustment after setting the exposure to cusom speed.
Any idea, what auto adjustment the internal camera firmware/algos could do after setting my own exposure? And what kind of AWB algorithm do you use in the camera firwmare (Gray World ?) ?
Thanks

4

@watchever

[quote=“watchever, post:1, topic:5298”]
Model number of the product(s)?
IMX467

I noticed your camera module, is it a typo?

You can tell me the correct camera module, I will try to reproduce the state.

Raspberry Pi can use grayscale time or Bayesian algorithm to calculate white balance, you need to check the tuning file json file for details. It also depends on the model of your camera.

5

Yes sorry IMX462. And do you mean that the awb algo is not directly implemented in your camera firmware?
Thanks

6

@watchever

Yes, implemented by Raspberry