How to test the quality of hemispherical camera? Home security monitoring equipment monitoring cameras looking for answers.

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1. test of color reducibility of hemispherical camera

The color monitor that should be selected when testing this parameter. First, observe people and costumes from a distance to see if there is any color distortion, compare brightly colored objects, and see the sensitivity of the hemispherical camera. Put the color album in front of the hemispherical camera to see if the outline of the picture is clear, too light or too thick, and then shoot the moving color object again to see if there is any color difference tailing, delay and blur. The test conditions are as follows: When the first generation illumination of the camera is 50V, the measurement should be made at the illumination of 50 10V, that is,10V is added to the first generation illumination of the camera in each hemisphere, and the aperture is kept in the closest state.

2. Measurement of transparency

When testing multiple hemispheric cameras, use the same lens (it is recommended to use fixed focal length and two variable lenses), and count the given scale lines *** 10 vertical lines and 10 horizontal lines clearly and accurately according to the central circle of the test card appearing on the left and right sides of the monitor screen. Represents vertical definition and horizontal definition respectively, and the corresponding groups have given the number of lines. Such as vertical 350 lines and horizontal 800 lines, it is best to use black and white display at this time. When testing, you can focus on the distant scene, or you can focus while measuring. It's better to use both, and you can see the difference (convergence) of this camera. Step 3: Lighting

The hemispherical camera is placed in a darkroom, with movable 220V self-lighting lights and voltage regulators in front and behind the darkroom. The voltage regulator adjusts the brightness of the lamp in the darkroom. The voltage can be adjusted from 0V to 250V, and the indoor lighting can also be adjusted from the darkest to the brightest. During the test, record a minimum illuminance value when the aperture of the camera is opened to the maximum (dim the movable light with the voltage regulator until the built-in picture in the darkroom can't be seen clearly), then record the next minimum illuminance value when the aperture is adjusted to the minimum, or adjust and turn off the front and rear lights respectively.

4. Backlight compensation of hemispherical camera

There are two ways to test this parameter: one is to turn on the voltage-regulating lamp in front of the camera in the darkroom and turn it to the brightest, and then put a picture or text under the lamp to shoot the hemispherical camera to see whether the picture and text can be seen clearly and whether the picture is dazzling. Adjust the al and AX shift switches to see if there is any change and which effect is the best. The other is to shoot the camera out of the window in sunny conditions to see if you can see the images and words clearly at this time.

5. Hemispherical camera power consumption

The minimum working voltage and current are measured by multimeter, and the voltage is adjusted by small voltage regulator. At present, the generation of images mainly comes from CCD cameras. CCD is the abbreviation of chargecoupleddeice, which can convert light into charge, store and transfer the charge, and also take out the stored charge to change the voltage, so it is an ideal camera element. The CCD camera composed of it has the advantages of small volume, light weight, no influence of magnetic field and impact resistance.

Contact: Zhang Lihong