To adjust the focus of the Camera PRO-642/742, you must first open it.
1. The first step is to remove the hood of the camera.
You will have to apply a good deal of force to do so the very first time.
2. Afterward, you need to twist the camera open.
3. You will find that the infrared board is in your way .
So you need to disconnect the infrared board first. Locate the plug and pull disconnect the board gently.
4. There are 2 screws that hold the board on the camera assembly. You need to remove them.
5. The board can then be separated. Put it on the side. The next step is to loosen the screw on the neck of the lense. Once loosed, you can adjust the focus by turning the lens clockwise or counter-clockwise.