What is minimum illumination?
Minimum illumination is related to the camera lens. It is an important indicator to measure the surveillance camera which represent environmental sensitivity.
Illumination is generally represented by Lux(Note 1), 0Lux means that camera can shoot even in the absence of light.Most surveillance cameras minimum illumination are usually between 0Lux to 0.1Lux.
In addition to the resolution and shooting distance, surveillance camera minimum illumination suit for environment is also a important factor.
*(Note1)Lux
0 means more sensitive to light, conversely, less sensitive.
Low illumination surveillance camera
Low illumination surveillance camera have lower illumination than common surveillance camera, suitable for use in environments with insufficient light sources, such as parks, parking lots, construction sites, etc.
Low illumination is a extend name, there is no unified technical specification in the surveillance system industry, it can use in many places if it support infrared so that picture is black and white;and starlight color camera has low illumination characteristics can picture colorful things at night.
Different environments are suit different cameras, you must ask expert to conduct an environmental assessment and select camera.
There are many factors that affect low illumination camera, such as CMOS sensor(Note2), shutter(Note3), aperture(Note4) and DSP(Note5).
*(Note2)CMOS
CMOS sensor determines the image of low illumination.Increasing the area that can absorb light in a single pixel of CMOS sensor which means can increase sensitivity effectively, the light-receiving area, and reduce the influence of noise.
The size of CMOS sensor also affects low illumination.For the same pixel, the larger the size, the larger the photosensitive area allocated to each pixel, the greater the amount of light passing through an exposure period, and the better the low-illuminance effect.
*(Note3)Shutter
Controlling the amount of light entering by adjusting the shutter time.
Increasing the amount of light entering by slowing down the shutter so that the ambient light is higher than the minimum illumination.Although the image can be imaged but it is easy to produce the phenomenon of blur.
*(Note4)Aperture
The lens aperture affects the amount of light entering.
The larger the aperture, the greater the amount of light, and thus the better the color effect. Otherwise, the worse the effect. However, the larger the lens aperture, the shallower the depth of field, which means the smaller the focus range in the scene.
*(Note5)DSP
DSP is an important process of image noise reduction and noise filtering, which is related to the clarity and stability of the picture and quality.
DSP can be used to correct and optimize the signal when the environment is dark, so that the noise and illumination can be minimized, thereby getting a clearer picture.
(Choosing high definition to watch)