Why is a distance of about 7 meters required for adjusting car headlights?

[DominicLynn]

In fact, adjusting car headlights does not necessarily require a distance of exactly seven meters. The adjustment can be performed as long as the front of the car is 3-10 meters away from the wall. The main reason is that within this 3-10 meter range, the light and dark boundary of the vehicle's headlights can be clearly observed, which helps in determining the height of the headlights. Headlight adjustment level 0 is the highest: This is because level 0 represents the initial height of the headlights, which is the factory-set horizontal position of the vehicle's lighting. At level 0, the headlight bulbs will not have any positional deviation. Vehicle headlights typically have four adjustment levels: 0, 1, 2, and 3. The higher the number, the lower the headlight height. Beam angle deviation: Under normal circumstances, factors such as cargo load, tire pressure, and road gradient can cause the headlight beam angle to deviate, necessitating manual adjustment of the headlight height. Both the low beam and high beam heights can be adjusted using the headlight adjustment button.