Q. 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.
– The focus is out at the night if it is set during the day, and vice versa.
– It is caused by the focal point location shift according to wave length difference between visible light and IR light.
– 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