The focus is off when camera shift from night time to day time.

It is a phenomenon that occurs commonly on box type cameras with separate lenses.

1. Issue
   —  The focus is out at the night if it is set during the day, and vice versa.

2. Cause

   — It is caused by the focal point location shift according to wave length difference between visible light and IR light.

3. Solution

     — It is recommended to use IR light lens that reduces the difference of wave length between visible light and IR light.

     — It is recommended to use a camera featuring simple focus function which readjusts the focus according to day and night.

      The 2 measures above are the most effect methods to reduce the focus difference occurred due to day and night shift.

       
       Image 1)  visible light

      
       Image 2) IR light