Let's take a look at the steps to adjust the focal length after installing the surveillance video:
(1) Mount the lens correctly on the camera.
(2) Open the lens as much as possible to the aperture (the purpose is to reduce the depth of field to accurately find the imaging focus).
(3) Push the lens to telephoto status with Zoom In, take a close-up shot of an object other than 10m, and adjust the focus by adjusting the focus (Focus).
(4) Perform Zoom Out, which is the reverse of the previous step, to pull the lens back to the Wide state. At this time, the screen becomes a panoramic image containing the close-up objects described above, but focus adjustment cannot be performed at this time (Note : If the image becomes blurred at this time, the focus cannot be adjusted, but the next focus adjustment is prepared.
(5) Loosen the hexagon socket screw that fixes the front focal length adjustment ring on the front end of the camera, and rotate the rear focal adjustment ring (for cameras without a rear focal adjustment ring, rotate the lens directly to bring its built-in back focus ring) until The screen is clearest, and then tighten the Allen screw.
(6) Push the camera to the telephoto state again to see if the close-up object just taken is still clear. Repeat the above steps a, b, and c if it is not clear.
(7) Usually only one or two rounds are required to complete the back focus adjustment.
(8) Tighten the Allen screw and adjust the aperture to an appropriate position.
Steps to adjust focus after installing video surveillance
In some applications, it may happen that when the lens focus ring is adjusted to the extreme position, the image cannot be clearly seen. In this case, you must first confirm whether the lens interface is correct. If it is correct, you need to adjust the back focus of the camera. According to experience, in most applications where a camera is equipped with a power zoom lens, it is often necessary to adjust the back focus of the camera.