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Huaqiang Security Network News ] What is the adjustment method for the intercept after the fixed focus lens? Use the camera's automatic electronic shutter function to adjust the lens aperture to the maximum, the focus ring to adjust according to the actual distance of the scene, and then adjust the back intercept until the image is the clearest. What is the adjustment method for the back intercept of the zoom lens?
1. Turn on the camera's automatic electronic shutter function.
2. Use the controller to adjust the lens aperture to the maximum.
3. Point the camera at an object 30 meters away, focus to infinity. Most of the lens is facing the lens and rotate the front focus adjustment ring clockwise to the head.
4. Use the controller to adjust the zoom of the lens to push the scene to the farthest position. Adjust the intercept of the lens to make the scene clearest.
5. Use the controller to adjust the lens zoom to zoom the scene to the nearest, and fine-tune the lens to make the scene clearest.
6. Repeat steps 4-5 several times until the scene is always clear during zooming.
Infrared lamps have different powers and 715, 830nM wavelengths. What is the choice of wavelength?
1. If the user does not mind that the infrared light is visible to the naked eye, the 715nM infrared light should be preferred because of its long illumination distance.
2. If you consider the red storm problem, you must use 830nM infrared light, you should use low light camera.
3. Select a lens with a relatively large aperture.
4. The divergence angle of the infrared lamp should match the field of view of the lens.
5. The maximum illumination range depends on the weather conditions, the reflectivity of the object and the surrounding light level. The farthest projection range of the infrared spotlight is as follows.
500W = 150-200 meters 300W = 80-120 meters.
50W = 15-30 meters 30W = 5-15 meters.
The monitoring lens is installed in two ways: C type and CS type. Both threads are 1 inch 32 teeth and 1 inch in diameter. The difference is that the distance between the lens and the CCD target surface is different. The C type mounting seat is from the reference surface to the reference surface. The focal length is 17.562 mm, which is one more length than the CS-type CCD target surface, and the CS-type focal distance is 12.5 mm. Don't underestimate this one ring. Without it, the lens and camera will not be properly focused, and the image will become blurred. So before installing the lens, let's see if the camera and lens are the same interface. If not, you need to increase or decrease the ring according to the specific situation. Some cameras do not need a ring, but use a rear adjustment ring (such as Panasonic products). When adjusting, use a screwdriver to loosen the screw on the adjustment ring and turn the adjustment ring. At this time, the CCD target surface will be opposite to the mounting base (front). Exercise also plays a role in the circle. In addition (such as SONY, JVC) is similar to the rear image adjustment ring, its fixing screws are generally on the side of the camera. After loosening, adjust one of the gears at the top to make the image clear without adding or subtracting the ring.
AGCON/OFF (Automatic Gain Control): The camera has a video amplifier that amplifies the signal from the CCD to a usable level. The amplification is the gain, which is equivalent to a higher sensitivity. However, in a bright light environment, the amplifier will Overloading, the video signal is distorted. When the switch is ON, the lens aperture is fully opened under low light conditions, and the gain is automatically increased to obtain a clear image. When the switch is OFF, a natural and low-noise image can be obtained at low brightness.
ATWON/OFF (Auto White Balance): When the switch is turned ON, the characteristic/color temperature of the light source is detected through the lens, so that the white level is automatically and continuously set, and the gain of the red and blue signals can be controlled even if the characteristic/color temperature is changed.
ALC/ELC (Automatic Brightness Control/Electronic Brightness Control): When ELC is selected, the electronic shutter continuously and automatically changes the exposure time of the CCD image sensor according to the brightness of the incident light (generally continuously adjusted from 1/50 to 1/10000 second) . When this mode is selected, the ALC auto iris lens can be replaced with a fixed or manual iris lens.
It should be noted that in outdoor or bright environments, due to the limited range of ELC control, ALC lenses should be selected; under certain lighting conditions, the following may occur:
1 There is a strong tailing or blurring on high-brightness objects such as spotlights or windows.
2 The image is noticeably flickering and color reproducibility is unstable.
3 The white balance has periodic changes. If these phenomena occur, the ALC lens should be used. When the ELC mode is used for a fixed aperture lens, the depth of field of the image may be smaller than the depth of field obtained with the ALC lens. Therefore, the camera is in the ELC mode when the fixed aperture lens is fully opened. The depth of field will be smaller than when using an ALC lens, and objects far away from the image may not be in focus. When the lens is an auto iris lens, you need to switch the switch to ALC mode.
BLCON/OFF (Backlight Compensation Switch): When powerful and useless background illumination affects the sharpness of important objects in the center, the switch should be turned to the ON position.
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