(1) Elects when the choice infra-red lamp exposure is away from conservative
Gives the camera most low light intensity at the same time, but must give aperture F to want the evaluation, but the zoom lens only give 1:F generally the maximum value, namely aperture F minimum value (aperture actual size maximum value), F=f/D, then D is a definite value, when the f focal distance enlarges 10 times, F becomes very big (i.e. aperture actual size becomes very small). The luminous flux will come under the very tremendous influence.
(2) the infrared lamp to select the most important issue is the complete set of.
The infrared light and cameras, lenses, protective cover, such as complete sets of power supply. Programs in the design of comprehensive consideration of all the equipment design, use it as a night vision infrared illumination to consider the design of control systems engineering. Some people buy a finished camera, lens, protective cover, power supply even after the installation before going to consider purchasing infrared light, which is not correct, when considering the complete set of sex, with particular attention to the following issues.
1. Requested sizes IR waterproof camera
Nominal size of the camera increasing miniaturization of video cameras currently on the market sizes are 1 / 2 "1 / 3" 1 / 4 ", the camera size large, but received a large luminous flux, cameras small size, but received a less luminous flux, such as infrared light Nominal effective range is 1 / 2 "video camera under the conditions of test, such as the use of 1 / 3" or 1 / 4 "cameras, the effective distance will be subject to a certain extent. 1 / 3 "cameras flux is only 1 / 2" cameras luminous flux of 44%
3. The functional requirements of the camera and lens camera with automatic electronic shutter function, AGC automatic gain control function, the lens with automatic aperture, to accommodate the great changes in day and night illumination.
3. The use of black and white camera or a special color camera
CCD image sensor has a very wide light-sensitive spectral range, its light-sensitive spectrum includes not only the visible region, but also extended to the infrared region, take advantage of this feature can be visible at night without lights circumstances, the auxiliary infrared illumination also allows CCD map as a clear imaging sensor. The ordinary color camera in order to be able to transmit color signals, the output signal from the CCD device to separate out the three kinds of green-blue-red color video signal, and then synthetic color television signal, the light-sensitive spectrum only in the visible region.
4. Require selection of low-light cameras
The most low-light camera photo scene when the light intensity is low to a certain extent Ershi camera output video signal level as low as the value of a provision of the value when the scene brightness. Determination of this parameter should be specified the size of the lens aperture F. For example, using the F1.2 lens, when the scene was the illumination of the value of photography as low as 0.02Lx, the camera outputs a standard video signal amplitude 700mv amplitude of 50% -33%, claimed that the best illumination for this camera for 0.02Lx / F1.2.
SecurityCamera2000.com provided by the above knowledge