Here is how to disable autofocus during the day to night and night to day transition.
You will need to have Windows and local access to the camera, you can make work via the tunnel.
Open tunnel to camera
Open port 30001 to port 30001, this will allow the control to start video
Load the Active-X control and when you can see video
Right-Click video and you will see a menu
Click on “Sensor” and look for “Zoom Focus” last tab on the right.
You will need to change “Standard mode” to “debug mode” lower left, this will allow you to change the values.
Make sure the “D/N Auto Focus” is not checked ( it is checked by default )