Auto exposure times with IMX519

I have an Arducam 16MP IMX519 camera module.
For a webcam I want to use libcamera.
Photos should be taken during the day and at night with long exposure times.
I can take good night photos with
libcamera-still --shutter 25000000
I have already been able to make settings in imx519.json (is it the right way?)
With these settings it only has an effect if I change the value 100:
“exposure_modes”:
{
“normal”:
{
“shutter”: [ 100 , 50000000, 100000000, 200000000, 300000000 ],
“gain”: [ 1.0, 2.0, 4.0, 6.0, 8.0 ]

Hi,
Can you tell me more detailed information regarding your problem?

Ich möchte eine Webcam bauen, mit Fotos alle 10 Minuten. Am Tag macht sie Fotos mit 100ms Belichtungszeit day,
in der Nacht soll sie dann ansprechende Fotos mit langer Belichtungszeit machen (mehrere Sekunden).
night

I want to build a webcam with photos every 10 minutes. During the day she takes photos with 100ms exposure time,
at night she should then take attractive photos with long exposure times (several seconds).

Hi,
The camera can not be used as a webcam. The web server could not get the image from the libcamera. If you want to use the camera as a webcam, you need to modify the interface for capturing images.

I make every 10 minutes a photo.
See:https://www.burgenlandblick.at/
This is the camera: https://www.burgenlandblick.at/webcam/happytest/
The
or
https://www.foto-webcam.eu/