How to install and debug the webcam is very simple. Usually, as long as the lens is installed correctly and the signal cable is connected, it can work when the power is turned on. However, in actual use, if the lens is not installed correctly and the state of the webcam and lens is adjusted, the expected use effect may not be achieved. The following is a brief introduction to the correct use of the webcam.
1. Install the lens
The webcam can only be used if it is connected with a lens. Generally, suitable lenses should be selected according to the actual situation of the application site, such as fixed-focus lens or zoom lens, manual aperture lens or automatic aperture lens, standard lens or wide-angle lens or telephoto lens, etc. In addition, attention should be paid to whether the interface between lens and camera is C-type interface or CS-type interface. The threads of C-type interface and CS-type interface lenses are 1 inch and 32 teeth with a diameter of 1 inch. The difference is that the distance between lens and CCD target surface is different. The distance between C-type mounting base and focus is 17.562 mm, which is longer than CS-type distance from CCD target surface by a special connecting ring, and CS-type distance from focus is 12.5 mm. Don't underestimate this loop. Without it, the lens and camera can't focus properly, and the image becomes blurred. Therefore, before installing the lens, check whether the camera and the lens are the same interface mode. If not, you need to increase or decrease the connection ring according to the specific situation. Some network cameras do not need to connect the ring, but use the rear image adjusting ring. When adjusting, loosen the screws on the adjusting ring with a screwdriver and turn the adjusting ring. At this time, the CCD target surface will move backward (forward) relative to the mounting base, and also play the role of connecting the ring.
When installing the lens, first remove the protective cover of the webcam and the lens, and then gently screw the lens into the lens interface of the webcam and put it in place. For an automatic aperture lens, the control line of the lens should also be connected to the automatic aperture interface of the webcam. For an electric two-variable lens or three-variable lens, as long as the rotating lens is in place, it is temporarily unnecessary to correct its balance state (only after the post-focusing adjustment is completed, it is necessary to finally correct its balance state).
2. Adjust lens aperture and focus
Close the electronic shutter and backlight compensation switches on the webcam, aim the webcam at the scene to be monitored, and adjust the aperture and focus ring of the lens to make the image on the monitor the best. If the webcam is used in an occasiON with a large change in illumination, it is best to match the automatic aperture lens and turn the electronic shutter switch (ELC) of the webcam OFF. If the manual aperture is selected, the electronic shutter switch (ELC) of the webcam should be turned on. When the application site is brightest (the maximum ambient illumination), the lens aperture should be opened as wide as possible and the image should still be the best (the image should not be too white and overloaded), and the lens is adjusted. Install the protective cover and mount the bracket. Because the aperture is large and the depth of field is relatively small, the definition of the whole monitoring site should be taken care of as much as possible when focusing on the focal length. When the field illumination decreases, the electronic shutter will automatically adjust to slow speed, and with a larger aperture, the image can still be satisfied.
In the above adjustment process, if you don't pay attention to opening the aperture of the lens as large as possible when the light is bright, but closing it relatively small, the electronic shutter of the network camera will be automatically adjusted at a low speed, so a better image can still be formed on the monitor; But when the light is dim, because the aperture of the lens is relatively small and the electronic shutter is already at the slowest (1/50s), the imaging at this time may be dim.
3. Rear focal length adjustment
The adjusted back focal length is also called back focal length, which means that when the standard lens (standard C/CS interface lens) is installed, the image of the photographed scene can be just formed on the target surface of CCD image sensor. Generally, the back focal length of the webcam has been properly adjusted when it leaves the factory. Therefore, in the application with fixed-focus lens, it is generally not necessary to adjust the back focal length of the camera.
In some applications, when the lens focus ring is adjusted to the extreme position, the image still cannot be clear. At this time, it is necessary to confirm whether the lens interface is correct. If it is confirmed, it is necessary to adjust the back focal length of the webcam. According to experience, in most applications where the webcam is equipped with electric zoom lens, it is often necessary to adjust the back focal length of the webcam.
The steps of adjusting the back focal length are as follows:
A. install the lens on the camera correctly.
B open the lens aperture as far as possible (the purpose is to narrow the depth of field and find the imaging focus accurately).
C. Zoom In to push the lens to Tele state, take a close-up of an object 10 meters away, and then adjust the Focus to make the close-up image clear.
D. Zoom Out opposite to the previous step to pull the lens back to a Wide state. At this time, the picture becomes a panoramic image containing the above-mentioned close-up object, but at this time, no focus adjustment can be made (note: if the image becomes blurred at this time, the focus cannot be adjusted), but the next back focus adjustment is prepared.
E. loosen the hexagon socket screw used to fix the back focus adjusting ring at the front end of the webcam, and rotate the back focus adjusting ring (for webcams without back focus adjusting ring, directly rotate the lens to drive the built-in back focus ring) until the picture is clearest, and then temporarily tighten the hexagon socket screw.
F. Push the lens back to the telescopic state to see if the close-up object just shot is still clear. If it is not clear, repeat the above steps a, b and c.
G. in the telescopic state, if the close-up object is clear, tighten the hexagon socket screw and adjust the aperture to an appropriate position.
At this point, the webcam and lens are debugged