What's low illumination for security camera?
Low illumination camera introduction
Low illumination camera means the camera has capability to capture high clarity images under low light/illumination condition.
Illumination, i.e., light intensity, is a physical term, refers to total accepted visible light energy on a unit area. Unit: Lux.
Different security cameras have different Lux value or low illumination performance. 0Lux means under total darkness (no light), camera can capture images. Typically, the camera's lux value is 0Lux or 0.1Lx, the value of the illuminace value depends on lens'aperture (F value), the lower of the F value, the smaller is the required lux value. Color camera's Lux is between 0.0004LUX and 1LUX, B/W camera's Lux 0.0003~0.1LUX (When added with light sources/artificial light, the Lux can be 0Lux).
- The minimum illumination value for capturing images.
- 0.1Lux: Dark Grade (Normal)
- 0.01Lux: Moon Grade (Excellent)
- 0.001Lux or below: Star Grade (Superb)
Low illumination technology
Low illumination Image Sensor
Sony developed the Super HAD CCD image sensor, utilizing this CCD sensor, its color minimum illumination can reach 0.01Lux, and B/W minimum illumination can reach 0.001Lux (also can use articial light to reach 0Lux).
Sense-up or digital slow shutter, it's a kind of technology to improve the camera's low illumination performance, and its working theory is increasing the total amount exposure of single-frame CCD to enhance the sensitivity of the camera. With this method to provide higher sensitivity in low light conditions.
When the Sense-up/DSS is functioning, the image noises will be amplified, if utilizing the digital noise reduction, the image quality will be better, such as Sony Effio cameras provide 3 dimensional digital noise reduction (3D-DNR) function, through using DSS technology, 3D-DNR, and its unique AGC control, can improve the brightness of image, and avoiding motion blur, and reducing image noise, which is perfect for low illumination environment.
IR-CUT Filter (Removable ICR)
IR-CUT filter is a mechanical and motor drived component inside of camera, it is located between lens and CCD image sensor. Camera has built-in IR-CUT filter can provide true day/night video surveillance. It can provide day mode and night mode switching automatically.
In night mode, the inside filter will remove, hence allowing unnatural lights (ie.,Infrared) enter into image sensor to enhance low illumination performance. In day mode, the inside filter will be inserted between lens and image sensor to filter unnatural lights enter into image sensor, therefore to provide true color reproduction crisp images.
Tags: IP Camera